The Buccaneers signed the four-time All-Pro on Tuesday after he spent the first seven weeks of the season under suspension from the NFL for violations of the league's personal conduct policy.
He has one week remaining on the suspension, but was allowed to work out with the team's strength and conditioning staff.
Brown is not yet allowed to practice with the team, but can participate in meetings. He also was required to test negative for COVID-19 for six consecutive days before he was allowed to enter the team facility.
Arians said Brown is in "great shape" and should be "ready to go next week."
When healthy, the Buccaneers offense provides veteran quarterback Tom Brady with a well-stocked arsenal of pass catchers. Brown will play alongside Mike Evans and Chris Godwin at wide receiver. The Buccaneers also have Rob Gronkowski and Cameron Brate at tight end and running backs Ronald Jones and Leonard Fournette on their roster.
Godwin will miss the team's Week 8 game against the New York Giants due to a broken finger. Arians said he is optimistic the wide receiver can return in Week 9. The Buccaneers coach referred to Brown as an "insurance policy" when asked about Godwin's timeline for a return.
"He wants to play," Arians said of Brown. "If you want to play, you've got to do it."
Arians said he told Brown that he should "go to football practice, go to work, come home and go back to work" in their conversation on Wednesday.
"He's all in," Arians said. "I don't think we'll have any problems with those things."
Brown, 32, had four catches for 56 yards and a touchdown in one game with Brady and the New England Patriots during the 2019 season. The seven-time Pro Bowl selection had 104 catches for 1,297 yards and a league-high 15 touchdowns in 15 games in 2018.
Brown's 86 receiving yards per game rank fourth in NFL history.
The Buccaneers (5-2) face the Giants (1-6) at 8:15 p.m. EDT on Monday Night Football at MetLife Stadium in East Rutherford, N.J.