Former NFL quarterback Johnny Manziel, the 2012 Heisman Trophy winner, worked out last week for the Canadian Football League team that owns his rights, according to a report from TSN and confirmed by ESPN.

The Hamilton Tiger-Cats put Manziel through a series of workouts in Buffalo over two days, but the organization decided there were "too many red flags" to sign him now, the report said. The Tiger-Cats plan to retain their rights to Manziel through a roster mechanism known as a "negotiation list," in the event that he becomes a more realistic option.

Manziel, 24, hasn't played football since the Cleveland Browns released him after the 2015 season. He told ESPN in January that he had achieved sobriety and wanted to get back on the field. In a text to ESPN, he said is goal was to "PLAY FOOTBALL. A pre season game, anything I don't care what it is. Only need one team to believe in me and I'll do anything to make that a possibility."

Manziel was technically suspended for the first four games of the 2016 season for violating the NFL's substance abuse policy. He also faced further discipline as a result of domestic violence charges that later led to an agreement with the Dallas County district attorney's office to have charges dropped if he met certain conditions. Regardless, no NFL team has been confirmed to have expressed interest in signing him.

The Tiger-Cats, who have lost their first eight games of the season, recently hired former Hawai'i coach June Jones as their head coach. Their negotiation list also includes quarterbacks Robert Griffin III and Colin Kaepernick, among others.

They intended to hire Griffin's former coach at Baylor, Art Briles, as offensive coordinator earlier this week. But the team reversed its decision in response to outcry over Briles' role in Baylor's handling of allegations of sexual assaults by students, including football players.