Jenrry Mejia has been cleared to resume baseball activities after being diagnosed with a hyperactive thyroid gland.

The pitching prospect returned to camp with the Mets on Friday.

He has been advised by doctors not to eat seafood, which is rich in lodine, but he does not have to take medication.

"Everything is doing great. Everything is going well," Mejia said. "They said everything is looking great and I can do every activity, but don't eat fish. It's like Jose Reyes.

"They said (the thyroid) is too quick, but it's normal right now. They don't want me to make it faster."

Reyes was diagnosed with hyperthyroidism during spring training in 2010 and missed the first five games of the regular season.