A.J. Puk's new Summer Camp haircut has A's Sean Manaea in disbelief

Like most youngsters attending a summer camp, A's pitching prospect A.J. Puk wanted to make a good impression upon his arrival.

But no one was ready for Puk's appearance Sunday.

The prized left-hander showed up to the Oakland Coliseum for the A's Summer Camp workout minus his trademark long blonde hair.

With our All Access Daily newsletter, stay in the game with the latest updates on your beloved Bay Area and California sports teams!

Subscribe  SIGN UP HERE

Yes, Puk got a haircut. Not just a trim. It's all gone.

Teammate Sean Manaea couldn't believe the rookie cut all of his hair off.

Sometimes, everyone needs a fresh look, including Puk, who was known for his flowing hair.

Hair or no hair, the A's are expecting big things from Puk this season. The 2016 first-round draft pick will compete for a spot in Oakland's rotation. If Puk and fellow pitching prospect Jesus Luzardo win starting jobs, the A's could have one of the best rotations in baseball.

Athletics

Find the latest Athletics news, highlights, analysis and more with NBC Sports Bay Area and California.

Wilson praises Athletics' young core after walk-off vs. Rangers

Report: Athletics promoting top prospect Kurtz to big leagues

[RELATED: Manaea might wear mask during starts]

Manager Bob Melvin used Puk out of the bullpen last season, with the left-hander appearing in 10 games. The 25-year-old posted a 3.18 ERA and 13 strikeouts in 11 1/3 innings pitched.

But now, Puk, without his hair, will look to help the A's win the World Series by being a part of their rotation.

[SPORTS UNCOVERED: Listen to the latest episode]

Contact Us