"Let's see this weekend," Castro said Monday morning. "Maybe I can get into a game."
Cubs manager Rick Renteria, however, said later Monday that Castro's return to game action may not occur until next week.
Castro hurt himself while sliding into second base in a game March 2. The Cubs said he would be out seven to 10 days.
He's been getting daily treatment while awaiting a return to baseball activities. It's doubtful he'll accompany the team to Las Vegas on Saturday and Sunday when it plays the New York Mets.
"I'll just stay here," he said.
The Cubs have split-squad games in Arizona those days as well, so Castro could still play. He injured his left hamstring running the bases last season, causing him to miss two weeks of spring training.
"When I do work I try to do it on both sides, to be strong on both sides," Castro said.
Castro was 2-for-2 this spring before his injury.