Surgery was deemed necessary after an MRI on Roethlisberger's elbow Sunday night. The surgery is expected to take place this week, per the team.
"This is shocking and heartbreaking for me, to miss this much of a season and feel like I am letting down so many people," Roethlisberger said in a statement. "I can only trust God's plan, but I am completely determined to battle through this challenge and come back stronger than ever next season."
The season-ending news is a brutal blow for the 0-2 Steelers, who hoped to bounce back after missing the playoffs in 2018.
Roethlisberger is coming off of a 2018 campaign in which he led the NFL in passing yards (5,129).
Roethlisberger signed a two-year extension with the Steelers during the offseason and is under contract through the 2021 season. For a 37-year-old quarterback who has contemplated retirement in the past, it will be interesting to see what the future holds for the 16-year pro.
"The Steelers committed three years to me this offseason and I fully intend to honor my contract and reward them with championship level play," Roethlisberger added. "I will do all I can to support Mason and the team this season to help win games. I love this game, my teammates, the Steelers organization and fans, and I feel in my heart I have a lot left to give."
The 2018 third-round pick saw his first pro-action in Sunday's loss, finishing 12-of-19 passing for 112 yards, 5.9 yards per attempt, two touchdown tosses, one interception (which went through the hands of Donte Moncrief) for a 92.4 QB rating and took no sacks in two quarters of play.
As the Steelers head into the unknown sans Roethlisberger for more than a few games for the first time since his rookie season in 2004, the positive is that Rudolph didn't look overwhelmed in his debut.
A personnel man for an opposing team told NFL Network's Mike Garafolo on Monday that Rudolph's display could provide a modicum of hope for the Steelers.
Rudolph looked comfortable managing the pocket Sunday, displayed poise and ability to get to his second read. There was still some roughness around the edges, but the hope is with regular practice and playing time moving forward, Rudolph could become a potential long-term answer for the Steelers.
The second-year signal-caller already received rave reviews from teammates after the loss for how he handled the situation.
"He handled himself really well," guard David DeCastro said. "Really proud of him, how he came in ready to go. He knew the playbook, had a big command, and he mixed some of the cadences, too. That was impressive."