The hard-throwing right-hander has been on the injured list since late April because of a sore elbow.
Eovaldi threw 11 of his 19 pitches for strikes and walked one during a 4-2 loss to visiting Louisville. He is set to travel with the Red Sox to Baltimore ahead of their series opener Friday and is expected to come off the IL on either Saturday or Sunday.
Eovaldi will pitch in relief when he rejoins the Red Sox, as the team previously announced.
"I feel really good. Fastball felt good, cutter felt good. I didn't throw any splits today, but I threw two curveballs and they felt really good coming out of the hand," Eovaldi told reporters Thursday. "I feel like I've gone through all the tests that I possibly can, so I feel like I'm ready to go. Mainly just use tomorrow as a recovery day and be ready to go either Saturday or Sunday."
Eovaldi has no record and a 6.00 ERA in four starts this season after signing a four-year, $68 million contract to remain with the Red Sox last December.