"I've been feeling good," Pineiro said.
Pineiro, one of four Cards starting pitchers on the disabled list, has been out with an irritation under his right shoulder in the lat muscle. He threw approximately 50 pitches in the bullpen on Saturday and reported no problems.
The next step for the righty is to throw 85 to 90 pitches in a rehab start at Double-A Springfield on Tuesday. If that goes well, he's expected to rejoin the Cardinals for his first start on April 13 in San Francisco.
"I think I'm ready," Pineiro said. "They just want to make sure everything goes fine on that Tuesday."
Pineiro went 6-4 in 11 starts for the Cardinals in 2007 after being traded from Boston on July 31. He signed a two-year contract with the Cardinals in October after previously pitching for the Seattle Mariners for seven years and splitting last season between St. Louis and Boston.
When Pineiro returns to the rotation, he'll join a group of starters that has performed well in the opening week of the season.
Through the Cardinals' first four games, the rotation was 3-0 with a 0.79 ERA and had combined for 18 strikeouts and 10 walks in 22 2/3 innings.
Pineiro has been paying attention to his fellow starters and has liked what he's seen so far.
"I don't want to come in there and mess anything up," Pineiro said. "I want to stay away. These guys are stepping it up and doing what they need to do. If we can hold it up till the big guys come back we should be OK."
If the members of the current rotation continue to pitch well, Cardinals manager Tony La Russa will have a difficult decision to make. Pineiro's return will mean someone will move to the bullpen or possibly be sent down to Triple-A Memphis.
"It would be a wonderful position to be in to have too much pitching," La Russa said before Saturday's game.
Nate Latsch is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.