TEMPE, Ariz. — About halfway through the exhibition schedule, top prospect Jo Adell has shown both his promise and the need to clean up a few parts of his game.

Adell, 20, is hitting .318 (7 for 22) in big league exhibitions with the Angels.

“He’s been on time with his swing,” Manager Joe Maddon said Monday. “He’s catching up to heavy velocity right now. He uses the (opposite field) gap well. You know, there’s a couple little technique things in the outfield, which I’ve already talked to (outfield coach Jesus) Feliciano about that and I think he’s gonna get better.”

Offensively, Adell has had trouble making contact, striking out 11 times already. He has not drawn a walk.

“He’s 20,” Maddon said. “He’s probably going to cut down on that as he gets more experience. … If Jo’s strikeouts to walks are disproportionate, it’s probably because he might be chasing a little bit more than anything. That’s not technique, in a sense, but that is a mental approach that might need to be clarified. And that happens from time to time. Everybody wants these guys in the big leagues right now. Sometimes you have to earn it. Always you should have to earn it.”

Adell came into a camp with an outside shot of making the Opening Day roster. Adell spent just about a month at Triple-A at the end of last season, so it was likely that he’d open this season at Triple-A and be up in the majors later in the season.

CUTTING FOR A CAUSE

Maddon hosted “Balding All Angels” before Monday’s game. Maddon, several coaches and players and General Manager Billy Eppler had their heads shaved in a show of support for the cause. The event benefited Miller Children’s and Woman’s Hospital in Long Beach.

Maddon has hosted similar events, although with different names, each spring since 2012, as manager of the Tampa Bay Rays and Chicago Cubs. His charitable foundation, Respect 90, has raised about $350,000 since its inception.

Among the coaching staff, bench coach Mike Gallego, pitching coach Mickey Callaway, catching coach Jose Molina, bullpen coach Matt Wise and special assistant Marcel Lachemann had their heads shaved. Players Cam Bedrosian, Tommy La Stella, David Fletcher, Luke Bard, Parker Markel and Mike Mayers participated.

VERSATILE FLETCHER

David Fletcher was scheduled to finish Monday’s game in center field, which he said would be the first time he’d played center field in a game at any level. The Angels had expanded his role to include the corner outfield spots a couple of years ago.

“He’s a great athlete,” Maddon said. “I think he can do anything. I think he could catch. … I think if you give him a challenge, he’ll figure it out.”

Outfielder Brandon Marsh took live batting practice on Monday morning. Marsh, who has been out for a couple weeks with a sore non-throwing elbow, could get into an exhibition game later this week. …

Relief pitcher Cam Bedrosian is going to be sidelined for a few days with back stiffness. Bedrosian is scheduled to throw a bullpen session on Wednesday and pitch in a game on Friday. …

The Angels are expected to start making their first cuts of the spring on Tuesday.