After missing nearly all of 2019 with an elbow injury, there is no guarantee Pittsburgh Steelers quarterback Ben Roethlisberger will return to the NFL.

"I've talked to people who have spoken with him, and he has some doubt whether he's really gonna play football again," ESPN's Chris Mortensen said on SportsCenter Monday.

Roethlisberger still hasn't begun throwing since his September elbow surgery.

The quarterback first suffered the elbow injury in Week 2, ending his 2019 season after just two games with zero touchdown passes.

Though he was placed on injured reserve, there was initially plenty of optimism about him returning at full strength in 2020.

"No one is concerned that next year is going to be a problem," a source told ESPN's Adam Schefter.

Head coach Mike Tomlin had a more tempered approach but still expected Roethlisberger back next season.

"He fully intends to come back from his injury, and everything we've heard, we're comfortable that's a strong possibility," Tomlin said in September, per Jeremy Fowler of ESPN.

However, there now appears to be a stronger chance the 37-year-old has played his last NFL game.

This could be a significant blow for Pittsburgh, not only because Roethlisberger is a six-time Pro Bowler who led the league in passing last season but also because of the quarterback struggles throughout 2019. Mason Rudolph and Devlin Hodges have been inconsistent over their 13 combined starts, totaling 18 touchdowns and 17 interceptions.

According to Mortensen, the Steelers could sign a veteran free agent like Philip Rivers, Eli Manning or Teddy Bridgewater this offseason if Roethlisberger is unable to return.