CINCINNATI -- The Bengals and Cleveland Browns failed to work out a trade that would have sent quarterback AJ McCarron to Cleveland, sources told ESPN's Adam Schefter.

According to Schefter, the Bengals notified the league of the proposed trade at 3:55 p.m. ET, and the Browns notified the league shortly after 4 p.m. ET. Because the Browns were late, the league denied the trade. Cleveland protested with the league asking that the trade be approved. The NFL rejected the Browns' protest.

The proposed compensation for McCarron would have been a second- and third-round pick in 2018, a source confirmed to Schefter. The Cincinnati Enquirer first reported the compensation.

McCarron has been the subject of trade rumors since the 2016 offseason after he filled in for an injured Andy Dalton and almost led the Bengals to their first playoff win under coach Marvin Lewis. McCarron completed 66.4 percent of his passes in seven appearances during the 2015 regular season, throwing for six touchdowns and two interceptions. In his lone playoff start, he completed 23-of-41 passes for 212 yards, one touchdown and one interception.

The Bengals said they would listen to offers for McCarron for the right price, and it seemed almost certain that McCarron would be elsewhere by the time the 2017 season came around. The team claimed quarterback Jeff Driskel off waivers last year with the intention of developing him if they got an acceptable offer for McCarron.

At the end of last season, McCarron expressed his appreciation to the organization, which sounded like he was preparing to say goodbye. However, a trade never materialized, and McCarron once again entered the season as Dalton's backup. He has taken three snaps in 2017.

McCarron, taken in the fifth round of the 2014 draft, is in the final season of his rookie contract. However, the Bengals could retain his rights next season because he did not spend enough time on the active roster as a rookie to accrue a year toward free agency. An arbitrator will have to decide whether he is a restricted or unrestricted free agent in 2018.