Brady had said last month that he was optimistic about being able to fully participate in June's mandatory minicamp. Arians said he wants Brady to take his time.
"I told him, 'Just take it easy,'" Arians said Friday after the Bucs' first rookie camp practice. "He wants to get his arm in shape and he's gotta take the time on that leg. You throw with your legs as much as your arm. He knows that, so just take your time and make sure you're right."
Rookie outside linebacker Joe Tryon, whom the Bucs selected 32nd overall in the NFL draft, did not participate in Thursday's practice because he has not passed his physical.
Arians said Tryon had a "slight scope" of his knee three to four weeks ago but should be ready for mandatory minicamp.
"He's real close, but we're not gonna take any chances," Arians said. "We're gonna take it slow. He'll be ready for mandatory minicamp for sure, maybe sooner."