PITTSBURGH -- Steelers general manager Kevin Colbert is optimistic that Ben Roethlisberger's rehab is going in the right direction and said he doesn't think the veteran quarterback "is at the end of the road."

Roethlisberger, who will turn 38 next month, had surgery on Sept. 23 to repair a season-ending elbow injury he suffered in Week 2. Colbert would neither confirm nor deny that Roethlisberger had Tommy John surgery, but said he remains on track in his rehab and has a checkup in Los Angeles on Feb. 21.

"All signs are good at this point, and where that goes, we're hopeful he can make a complete recovery," Colbert said. "As of right now, he's on schedule for that. Where it goes from here remains to be seen."

Roethlisberger is the last remaining quarterback drafted in 2004 who is with his longtime team, after Eli Manning's retirement and Philip Rivers' departure from the Chargers. Colbert believes Roethlisberger, a two-time Super Bowl champion, is still a valuable asset.

"He had an injury to his right arm, but other than that, he's relatively healthy," Colbert said. "We're not minimizing the right arm injury to a right arm quarterback, but we don't think he's at the end of the road."

Without Roethlisberger for most of last season, the Steelers had to rely on a pair of young, unproven backups, Mason Rudolph and Devlin "Duck" Hodges, to take the reins. The team went 8-6 on their watch and finished just outside the playoffs at 8-8.

The margin for error shrank with Rudolph and Hodges starting, placing more of a burden on the Steelers' defense. Still, Colbert said the team is comfortable going into training camp with that pair and Paxton Lynch -- a 2016 first-round pick who initially joined the practice squad before being elevated to the active roster -- as Roethlisberger's backups.

"Optimistically, [Roethlisberger] is on schedule to return and we hope to return to maybe even a better Ben Roethlisberger than he was previous to the injury," Colbert said. "In the meantime, we understand who our backups are. We're comfortable with who those backups are. I thought they did a great, representable job in 2019 under the circumstances."

Despite missing the postseason for the second year in a row, Colbert is optimistic about the direction of his team.

"We're all disappointed at 8-8," he said, "but I feel better moving into 2020 than I did moving into 2019 coming off of 9-6-1."