PHILADELPHIA -- Phillies general manager Ruben Amaro Jr. places a premium on pitching, which is why he has committed hundreds of millions of dollars to Cole Hamels, Cliff Lee and Roy Halladay.

The Phils have some good young pitchers coming up through the system, many of whom could be in the bullpen on Opening Day 2013. But here is a look at some of the pitchers currently throwing in the Arizona Fall League and winter ball.

They might not be on the Opening Day roster, but they could help out down the road.

Right-hander Kyle Simon

The Phillies acquired Simon from the Baltimore Orioles in the Jim Thome trade in June. He had been starting last season with Class A Frederick before Philadelphia put him in the bullpen with Double-A Reading, where he went 1-0 with a 1.42 ERA in 14 appearances. Simon is 2-2 with a 9.00 ERA in five AFL starts with Peoria, but the Phils don't read too much into that. Each team has to supply one starter in the AFL, and Simon is it -- even though he hadn't started since his time with the Orioles.

"He's probably wearing down a little bit," assistant general manager Benny Looper said. "And [starting] is not where we think he's going to reach the big leagues at. We think he'd be a bullpen piece."

Right-hander Lisalverto Bonilla

He had been having a nice season until he injured his right thumb clowning around in the team hotel before the All-Star Futures Game in July. Bonilla is 0-2 with an 11.67 ERA in six appearances with Leones del Escogido in the Dominican Winter League.

"He had been out since the All-Star break," Looper said. "That's three and a half months. It's taken him awhile to get back on track."

Right-hander Justin Friend

The Phillies selected Friend in the Minor League phase of the Rule 5 Draft in 2010. He went a combined 3-7 with a 2.75 ERA and 28 saves in 55 appearances with Class A Clearwater and Double-A Reading in 2011 and 4-1 with a 1.33 ERA and 25 saves with Reading and Triple-A Lehigh Valley last season. Friend is 3-1 with a 1.38 ERA in 13 appearances with Tiburones de La Guaira in Venezuela. He has an average fastball, which is why others in the organization are considered better prospects.

"He's a strike thrower," Looper said. "He's got to have real good command."

Right-hander J.C. Ramirez

He is one of the three players acquired in the Lee trade with Seattle in 2009, but he is not progressing like the Phils expected. After struggling as a starter, Ramirez moved into the bullpen last season and went 3-4 with a 4.01 ERA in 45 appearances with Reading and Lehigh Valley. He is 1-0 with a 10.80 ERA in five appearances with Tiburones de La Guaira in Venezuela. What's the problem? Ramirez has a good arm -- his fastball is in the mid-90s -- but he hasn't been able to develop a pitch to complement the fastball.

"He needs to come up with a second pitch," Looper said. "He picked up a split last year in winter ball, but it didn't really come on this year. His slider might be a little bit ahead. But he's a big kid with a good arm. He could use better command with his fastball, but more than anything, it's the development of his second pitch."

Right-hander Colby Shreve

He went 6-3 with a 3.69 ERA in 47 appearances with Class A Lakewood, Clearwater and Reading. Shreve is 0-1 with a 4.50 ERA in nine appearances with Peoria in the AFL. Shreve has an above-average fastball, but it has been average in the AFL.

"He has a good arm," Looper said. "He's probably wearing down some."