Pittsburgh is pausing the start of its Russell Wilson era.

The Steelers are riding with backup quarterback Justin Fields on Sunday in their season opener against the Falcons with Wilson sidelined due to a calf injury, NFL Network’s Mike Garafolo reported.

Fields, 25, was seen warming up on the field ahead of kickoff at Mercedes-Benz Stadium in Atlanta.

Wilson, named the Steelers’ starting quarterback just weeks ago, was listed as “questionable” over the calf issue, which “cropped up before the first training camp practices,” according to NFL.com.

The Super Bowl-winning quarterback, who spent the past two seasons with the Broncos, told reporters Friday, “If I’m ready to go, I will go.”

With Wilson, 35, officially sidelined for Week 1, Fields gets the nod Sunday in what will be his first game in a Steelers uniform.

The former first-round pick spent the past three seasons in Chicago before being traded to Pittsburgh in March.

Entering Week 1, head coach Mike Tomlin gave Fields a vote of confidence while discussing the possibility of him playing.

“I’m extremely comfortable if that’s the case, certainly,” said Tomlin, who previously hinted at a game-day “package” involving Fields.

Fields threw for 2,562 yards, 16 touchdowns and nine interceptions in 13 appearances last season.

The Steelers shook up their quarterback room this offseason with the addition of Fields and Wilson, who agreed to a one-year deal in March.

Pittsburgh traded 2022 first-round pick Kenny Pickett to the Eagles earlier this year while veteran backup Mason Rudolph signed with the Titans in free agency.

The Steelers kick off against the Falcons at 1 p.m.