Manny Machado may not be ready for Opening Day after experiencing a setback in his surgically repaired knee.

Machado has not appeared in a game this spring and was scheduled to undergo an exam Tuesday, but the 21-year-old has been hampered by scar tissue and has not resumed running.

"There's no sense in doing [the appointment] until he can really show them what he can do running," Buck Showalter said. "So that's got to get cleared up first, where he's back running again. And then he can completely clear him again."

The Baltimore Orioles open the season on March 31 against the Boston Red Sox.