Quarterback Johnny Manziel, a former Heisman Trophy winner who fizzled in the N.F.L. and was kicked out of the Canadian Football League, signed with the Alliance of American Football on Saturday night and will join the Memphis Express.

Manziel’s rights belonged to San Antonio of the spring league, but that team declined to sign him and Manziel was then free to join any of the other seven clubs. He was awarded through the A.A.F.’s waiver system to the Express, who have a league-worst 1-5 record.

“We are pleased to welcome Johnny Manziel to Alliance of American Football, which we’ve always described as a league of opportunity for talented players to launch or revitalize their pro football careers,” the Alliance co-founder Bill Polian said in a statement released by the league.

“We completed extensive background work to determine whether it would be appropriate for Johnny to play this season, and after consulting with many people familiar with his situation, we concluded that it would be good for him to resume his pro football career here at 5he Alliance.”