Sashi Brown said the team still does not know where Manziel was the final weekend of the regular season because the Browns had been more focused on hiring a coach and vice president of player personnel.
"We don't know where Johnny was," Brown said. "... I don't know where Johnny was the final game of the season."
USA Today reported that Manziel was in Las Vegas the night before the regular-season finale against the Pittsburgh Steelers.
The team will sit down with Manziel "at the appropriate time" for a conversation, Brown said.
"I know a lot's been written about him. What we expect is Johnny to have a good offseason and be ready to go. We're not in any panic to make any decision one way or another on him," Brown said. "He understands what's ahead of him and what he needs to do to have a career in this league and with the Browns."
Manziel was in the building for postseason assessments on his concussion and was cleared, Brown said, adding that the second-year quarterback was late for treatment the day of the season finale and was fined for it.
"How much can we do?" Brown said. "Johnny, he's an individual, he's a man, and he's going to have to own a lot of this, in terms of his future career.
"I'm not going to comment on the off-field stuff. I think it's important that he understands perfectly the circumstance that he's in and where he is in his career. Our expectation is he comes back ready to go and he's focused on being a great teammate."
Brown said the team also will assess the future of suspended wide receiver Josh Gordon once it knows whether he is reinstated by commissioner Roger Goodell.
"Could Josh come back to this roster? Yes," Brown said. "Is that necessarily going to happen? He's got to be cleared first by the NFL to get to that point."
If he is cleared, the organization will "sit down with Josh and see where he is," Brown said.
In a tweet Thursday, Gordon referenced his desire to return to football.
I just wanna play ball.. 🙏🏾
— Flash Gordon (@JOSH_GORDONXII) January 21, 2016
Brown will have the final say over Cleveland's roster, but he emphasized that he will work with the yet-to-be-named player personnel person, coach Hue Jackson and new director of strategy Paul DePodesta.
Brown said Jackson would have "huge input" into personnel decisions.