CINCINNATI -- The Reds certainly weren't expecting starter Alfredo Simon to lack command and velocity on his pitches when he worked twice last week. They were surprised when they learned the reason behind his struggles late Monday night when it was revealed that Simon has right biceps tendinitis. He was

CINCINNATI -- The Reds certainly weren't expecting starter Alfredo Simon to lack command and velocity on his pitches when he worked twice last week. They were surprised when they learned the reason behind his struggles late Monday night when it was revealed that Simon has right biceps tendinitis. He was scratched from his scheduled start in the Reds' 4-3 win over the Rockies on Tuesday.

Robert Stephenson, the Reds' No. 2 prospect and No. 33-ranked overall per MLBPipeline.com, was recalled from Triple-A Louisville to take Simon's turn. Reliever Jumbo Diaz was optioned to Louisville to make room for Stephenson on the roster. Simon's arm had been bothering him since his first start of the season, vs. the Pirates on April 8.

"That was something we didn't know. A lot of pitchers do it," Reds manager Bryan Price said. "You [think] you're going to figure it out, and it's going to go away and you'll do whatever you can in a covert fashion to get yourself in a position to be able to pitch without making it a big deal. There wasn't any point in time where any of us understood he was having some issues with his arm. But that did come to light last night in a late-night conversation. We responded rather quickly."

Cincinnati was fortunate that Stephenson was already slated to pitch on Tuesday for Louisville, which meant it did not have to put Simon on the disabled list. Price did not expect Stephenson to remain beyond Tuesday, citing the need for his continued development at Louisville.

"We'd love to see him really string together some good, consistent outings in Triple-A," Price said. "I think it still hasn't been [a case] where he's outperformed the level yet in his limited time in Triple-A, we'd like to see that."

The club expected that Simon would miss one start and is tentatively slated to pitch on Sunday vs. the Cubs.

"I can pitch like that. I guess they don't want it to get worse," Simon said.

In three games (two starts), Simon was 0-1 with a 12.15 ERA. He was roughed up by the Cubs last Wednesday as he lasted a career-low two-thirds of an inning but still managed to throw 49 pitches. He returned in relief with 27 pitches in one inning during Friday's loss at St. Louis and got hit hard again. The totals for these two games: 1 2/3 innings, nine runs (eight earned), three walks, two strikeouts and two home runs. During those outings, Simon's velocity dipped to the low 90s.

"I just dropped my arm down," Simon said. "That's why my ball was not moving, my two-seamer. The same thing when I threw my split [fingered fastball]. It was flat, so they could hit it."

Simon was given an anti-inflammatory injection in his shoulder. Price believed Simon could still give the Reds enough innings if he's ready to start Sunday.

"If he's healthy, I think he's capable of withstanding an early season workload, which typically would be five to six innings and somewhere in the neighborhood of 90-100 pitches," Price said.