Associated Press

SARASOTA, Fla. — The nagging question for the Cincinnati Reds in spring camp is who will fill out the starting rotation beyond top hurlers Aaron Harang and Bronson Arroyo.

The Reds are preparing to play an intra-squad game on Tuesday before launching into the Grapefruit League against the Philadelphia Phillies on Wednesday.

Free agent left-hander Jeremy Affeldt will face the Phillies on Wednesday. Matt Belisle, who went 8-9 with a 5.32 earned run average in 30 starts last year, will pitch Thursday’s home opener against the Minnesota Twins.

New Reds manager Dusty Baker said he’s expecting a big year from Belisle after a season in which the right-hander pitched well in most games for three or four innings, but then often was the victim of one bad inning.

‘‘It could be youth and it could be just a phobia,’’ Baker said. ‘‘When you think it’s going to come, it does. You have a negative vibe, and then your teammates start to wonder.’’

Belisle, 27, was the Atlanta Braves second round pick in the 1998 June draft. He came to the Reds in exchange for Kent Mercker during Atlanta’s stretch drive for the Eastern Division title in August 2003.

Ironically, Mercker is in camp trying to win a roster spot in the Reds bullpen.

Two other young pitchers have impressed Baker over the first eight days of camp: Left-hander Matt Maloney and right-handed prospect, Edinson Volquez.

Baker said he’s been wowed by Maloney’s breaking ball, as well as the quick movement and late break on his fastball. Maloney, a potential starter, has shown coaches that he’s willing to throw the fastball inside to right-handed batters.

‘‘Most left-handers are hesitant to throw it inside to right-handers because it might tail back over the middle of the plate,’’ he said. ‘‘The left-handers that I hated to face, Jerry Koosman and Frank Tanana would throw inside. It allows the pitcher to peel the plate like a banana.’’

Volquez, who was acquired from Texas in an offseason trade for outfielder Josh Hamilton, will need more refinement, Baker said.

‘‘Whoever scouted him did a good job,’’ he said. ‘‘He has to tighten his breaking ball a little and work on his command.’’