"No matter if you've had surgery or not, you're going to be sore the next day," manager Terry Collins said. "Everybody is after they pitch. So I'm sure he had some stiffness, but he felt good."
A far more important test will come Thursday, when Santana attempts to throw again. That could come in the form of playing catch off flat ground or a full bullpen session, depending on the level of soreness in his shoulder.
"It's possible his workload will be tailored to how he feels," general manager Sandy Alderson said. "But we won't know that until [Thursday]."
Throwing 29 pitches Tuesday afternoon against the Cardinals, Santana took the mound in a Major League game for the first time since undergoing left shoulder surgery in September 2010. He is scheduled to start again on Sunday, keeping him in line to pitch Opening Day against the Braves on April 5.