METAIRIE, La. -- Just two days after Dez Bryant finally returned to the NFL, it appears that his 2018 season is over.

The New Orleans Saints fear that Bryant tore his Achilles tendon on the final play of Friday's practice, a source confirmed to ESPN's Adam Schefter. The news was first reported by NFL Network, which said Bryant was to undergo an MRI.

A source told Schefter that testing on Bryant's Achilles is considered "a formality," as doctors already believe it is torn. The injury is expected to sideline Bryant for eight months, putting him on track to potentially be ready for training camp next year, when he again will be a free agent.

Bryant acknowledged a setback in a tweet Friday afternoon, writing, "This is the ultimate test."

Things was just starting to heat up for me... I won't question the man upstairs... this is the ultimate test.. thank you everyone for the prayers — Dez Bryant (@DezBryant) November 9, 2018

The Saints officially listed Bryant as limited in Friday's practice with an ankle injury. Coach Sean Payton did not acknowledge the injury when asked about Bryant after practice, before the news broke.

Bryant, who turned 30 on Sunday, had not been with a team since he was released by the Dallas Cowboys in April. He practiced for the first time Thursday.

The Saints could turn to another decorated veteran receiver, Brandon Marshall, who also impressed the team during a Tuesday workout, according to Schefter. The Saints also auditioned veteran receiver Kamar Aiken on Tuesday before opting to sign Bryant.

Bryant was unlikely to play this weekend at Cincinnati, regardless, so the Saints don't immediately have to alter their game plan, with Michael Thomas and rookie Tre'Quan Smith as their top two receivers. But they will almost certainly look to add depth at the position next week after placing Cameron Meredith on injured reserve Wednesday and Ted Ginn Jr. on IR last month.

The Saints could activate undrafted rookie receiver Keith Kirkwood from their practice squad for added depth Sunday.

Meanwhile, for Bryant, the injury continues a tumultuous year that began with a messy divorce in Dallas. The three-time Pro Bowler was released in April when he was due to earn $12.5 million.

Bryant said Thursday that he had been working out and getting his body and mind right all season -- but he also acknowledged that he was "thinking about preparing for the next year" before he got the call from Payton to come audition in New Orleans.

"Just lot of ups and downs," Bryant said when asked to describe the past two months. "Wanting to play football, thinking about playing football."

Bryant said he had turned down other opportunities to work out this season, without offering any specifics. He reportedly turned down at least one multiyear contract offer during the offseason.

Asked what made this situation different, Bryant pointed first to the opportunity to play with "big GOAT" Drew Brees and "baby GOATs" Thomas and running back Alvin Kamara.

The 6-foot-2, 220-pound Bryant was among the NFL's best in his prime. He recorded three straight seasons of at least 1,200 yards and 12 touchdowns from 2012 to 2014, and he earned Pro Bowl invites in 2013, 2014 and 2016.

But his production had been slipping in recent years as he battled foot and knee injuries; he had 69 catches for 838 yards and six touchdowns in 16 games last year. The Cowboys were ultimately ready to move on from what executive vice president Stephen Jones described as a "fiery" personality that could sometimes be a "distraction."

Bryant rejected the notion Thursday that he would be a locker room chemistry concern.

"I'm always gonna be me, you know, who I am. I'm not a bad guy. I've always been a good guy. You can ask my teammates -- my ex-teammates -- how I am," Bryant said. "I love the locker room. It's like family. Every locker room that I've been in from middle school, high school, college to the pros, it's always been like a family. You have a natural bond. It's more than just being in the locker room, it's outside of it too."

Bryant signed a prorated contract that will pay him $600,000. He could have made up to $500,000 in incentives for reaching specific reception totals: $50,000 for catching 25 passes in the Saints' remaining seven games after Sunday, an additional $100,000 for 30 catches, $150,000 for 35 catches and $200,000 for 40 receptions.