DETROIT -- Shelley Duncan was back with the Indians on Friday afternoon, only five days after being sent back to the Minor Leagues. He has served as the roster's yo-yo for much of the year, being called up and down multiple times.

Duncan is not about to complain.

"No," he said with a smile. "Hopefully I don't have to do it again."

Considering Sept. 1 -- the date on which rosters expand -- is right around the corner, Duncan will likely have the chance to stick with Cleveland for the home stretch. The utility man was promoted from Triple-A Columbus on Friday after the Indians placed rookie second baseman Jason Kipnis on the 15-day disabled list.

Indians head athletic trainer Lonnie Soloff said that Kipnis suffered a mild to moderate right hamstring strain while stretching prior to Thursday's game against the White Sox in Chicago. Kipnis, who underwent an MRI exam in Cleveland on Friday, is expected to miss three weeks with the injury.

"This guy has really given us a huge spark offensively," Indians manager Manny Acta said. "He gave us some stability at second base and in our lineup hitting in the second hole."

Kipnis has also been dealing with a right oblique issue that has bothered him for the past week. Infielder Luis Valbuena was also recalled from Triple-A Columbus, and was in the starting lineup at second base for Friday's tilt against the Tigers.

Cleveland optioned outfielder Ezequiel Carrera (.236 in 34 games for the Indians this season) to Triple-A to vacate a spot for Valbuena. At Triple-A Columbus, Valbuena was hitting .299 with 16 homers, 20 doubles and 71 RBIs in 101 games. He has hit just .136 (3-for-22) in two previous stints with Cleveland this year.

Acta said Valbuena and Jason Donald would split the playing time at second base for now.

Under typical circumstances, Duncan would have been required to remain at Triple-A for a period of 10 days after being optioned on Saturday. An exception can be made in the event of an injury to the Major League club, so the Tribe technically promoted Duncan to replace Kipnis on the roster.

Kipnis' stint on the disabled list is retroactive to Sunday due to the fact that Duncan's last game in the big leagues fell one day earlier. That means that Kipnis -- hitting .279 with six homers and 11 RBIs in 18 games -- will not be eligible to be activated until Cleveland's Aug. 30 home game against Oakland.

Needless to say, Duncan was thrilled to be back so soon.

"We're playing good," Duncan said. "It's getting to the time of year when the excitement really starts to ramp up."

Duncan, who is beginning his fourth stint with the Indians this season, has hit .246 with four home runs and 23 RBIs in 43 games. Against left-handed pitching, Duncan -- an option for first base, designated hitter and the corner outfield spots -- has hit .254 with one homer and 11 RBIs.

"Kipnis going on the disabled list obviously forced us to make a move," Acta said. "The thought process behind it is we have three left-handed-hitting outfielders that are playing every day, so there's not going to be that much opportunity for Carrera. We can have Shelley's right-handed bat here -- power off the bench."

Rehab work continues for Sizemore

DETROIT -- Indians center fielder Grady Sizemore continues to balance a rehab program that includes recovering from a sports hernia operation while also gradually regaining strength in his ailing right knee.

On Friday, head athletic trainer Lonnie Soloff indicated that Sizemore's progress has been good and the center fielder is on pace to return to game activities by early September. Right now, strengthening his knee is Sizemore's biggest concern.

"That's what we're being the most cautious with," Soloff said. "But he's very happy with how he feels."

Sizemore, who underwent the sports hernia procedure on July 21 after also aggravating his knee four days earlier, has started long toss as part of his throwing program. Soloff noted that the outfielder has also advanced to hitting baseballs in soft-toss sessions instead of simply off a tee.

On Saturday, Sizemore is scheduled to resume "land-based" running, according to Soloff. The Indians' trainer used that description given the fact that Sizemore has been running in a specialized anti-gravity treadmill, which reduces stress on the runner's legs.

"So far, so good," Soloff said. "But there's still no definitive timetable for his return."

Sizemore, who has had three stints on the disabled list this season, has hit .237 with 10 home runs, 21 doubles, 29 RBIs and 32 runs scored in 61 games.

Rainout with Twins rescheduled for Sept. 24

DETROIT -- The Indians' schedule -- already daunting down the stretch -- just became even more difficult.

On Friday, Cleveland announced that the Aug. 14 rainout with the Twins will be made up as part of a day-night doubleheader on Sept. 24. That means that the Indians will play 18 games within the final 16 days of this season. That falls within a stretch of 45 games over 44 days for the Indians.

Perhaps having a younger roster will help.

"I think it kind of helps a little bit," Indians manager Manny Acta said. "But it doesn't matter how old you are. Once you're in it at the end of the season, people will find energy to play and to get it done."

The Sept. 24 double dip against Minnesota will include a 1:05 p.m. ET game and a 7:05 p.m. ET contest. Fans holding tickets from the Aug. 14 game may exchange them for the day portion of the doubleheader or any remaining regular-season home game during the 2011 season (subject to availability).

That will represent the second twin bill in a span of five days for the Tribe.

Cleveland also has a doubleheader scheduled against the White Sox on Sept. 20 -- one day after playing a makeup game against the Mariners in Cleveland. The Indians, who only have two off-days (Thursday and Sept. 12) left this year, also have a doubleheader against Seattle slated for Tuesday at Progressive Field.

Acta hosting charity event on Thursday

DETROIT -- Indians manager Manny Acta is holding a special fundraising and fan appreciation event in downtown Cleveland on Thursday.

On Friday, the Indians and Acta's ImpACTA Kids Foundation announced that the Tribe skipper is taking part in a unique gathering from 5-9 p.m. ET on East 4th Street and at the Corner Alley. Acta wanted to give something back to the fans while also raising money for charity.

"To live life without positively impacting the lives of others is like not living at all," Acta said in a press release.

The evening will begin with a free public event on East 4th Street, where Acta will provide an official welcome to fans starting at 5 p.m. ET during a "Party-in-the-Park environment," according to the release. The Cleveland band Flip Side will play a free concert and mascots from the Indians and Cleveland Cavaliers will be on hand. Select 4th Street establishments will also support the event with discounted food and beverage specials until 7 p.m.

Then, Acta and other members of the Indians will take part in a VIP bowling event at the Corner Alley from 6-9 p.m. Indians players Asdrubal Cabrera, Shin-Soo Choo, Chris Perez and Justin Masterson are scheduled to attend, along with general manager Chris Antonetti, first-base coach Sandy Alomar Jr. and radio voice Tom Hamilton.

Fans can purchase VIP bowling tickets for $300 and corporate packages are also available. Contact info@impactakids.com or by visiting impactakids.org for more information. More than $15,000 in auction and raffle items will be awarded during the upcoming event and proceeds will benefit Acta's foundation as well as Cleveland Indian Charities.

Quote to note

"This is our job. We work -- max -- eight months out of the year. That's just what we have to do. The guy who works in a factory has to go in every single day, including Christmas Day. So that's it. We have to deal with it. That's what guys train for in the offseason and in Spring Training." --Indians manager Manny Acta, on the Tribe's tough September schedule

Smoke signals

• The $2.9 million signing bonus that the Indians handed to first-round Draft pick Francisco Lindor made up only a portion of the money spent by the Tribe on its selections this summer. Overall, Cleveland spent $8.225 million on signing bonuses for this year's Draft, according to Baseball America. That spending total ranked 12th in baseball. From 2007-11, the Indians have spent $33,179,300 on bonus money, which also ranks 12th in the Major Leagues.

• Outfielder Trevor Crowe, who underwent right shoulder surgery earlier this year, is set to begin a Minor League rehab assignment in the Arizona Rookie League this weekend, according to head athletic trainer Lonnie Soloff. The switch-hitting Crowe hit .251 with two homers, 24 doubles and 36 RBIs in 122 games for Cleveland last year.

• The Indians will need to promote a starting pitcher from Triple-A Columbus for the nightcap of Tuesday's doubleheader against the Mariners. Starter Carlos Carrasco (right elbow inflammation) is eligible to come off the disabled list, but Cleveland is planning on waiting until rosters expand on Sept. 1 before activating the righty.