Pickett will be out for Thursday's game against the New England Patriots, and while coach Mike Tomlin declined to give a specific timetable for the quarterback's return, he said the injury is not season-ending.
"They'll always come out of the O.R. with some information in that regard, but I'm just not privy to it as I sit here today," Tomlin said when asked about Pickett's recovery timeline. "That's why I framed it the way that I framed it. Rest assured, he won't be available this week."
Pickett underwent a "TightRope" procedure, sources told ESPN. The quarterback had a similar ankle stabilization procedure done on his left ankle in 2020 while at Pitt and returned after four weeks.
"He gets the most work," Tomlin said, explaining the decision to start Trubisky over Rudolph. "You can't give work to three guys, to be quite honest with you. Most of Mason Rudolph's work comes on a scout team offense and so Mitch has been positioned to get the work."
The Steelers also signed former Penn State quarterback Trace McSorley to the practice squad Monday.
Thursday will mark the seventh time in 26 games Trubisky has played because of an injury to Pickett. Tomlin, though, dismissed the idea that Pickett's repeated injuries are a concern.
"He was managing that ankle prior to yesterday," Tomlin said. "I think it was listed on the injury report every day last week and so it got aggravated, and we just did what was necessary in terms of addressing it.
"I don't know that we're viewing it as something that's chronic, particularly with something like an ankle injury, and so we're just dealing with this on a case-by-case basis as we sit here right now."
Earlier this season, Pickett left two games early with a knee bruise and a ribs injury. After taking over the starting job early in the 2022 season, Pickett exited two games early with concussions and missed one start.
The Steelers are 0-3 in games where Trubisky had to take over this season, while they went 2-1 last season when Trubisky either took over or started after Pickett had become the full-time starter in Week 5.
This season, Trubisky has completed 29 of 49 attempts for 273 yards with two touchdowns and two interceptions.
"He's been a franchise quarterback before," Tomin said of Trubisky. "He's comfortable in those shoes. He doesn't behave like a backup as being elevated, and I think those are things that make him attractive."
Trubisky will step in to face a defense that has held opponents to seven points or fewer in the past three outings. The Patriots' passing defense has also improved in its past three games, limiting opposing offenses to an average of 189.3 yards.
But tight end Pat Freiermuth expressed confidence in Trubisky while downplaying the notion that losing Pickett is deflating to the Steelers and their postseason hopes.
"It'll be the same offense." Freiermuth said Monday. "Mitch takes reps in practice, and we have full confidence in Mitch to execute the game plan. We're just full steam ahead."