When the Pittsburgh Steelers acquired both Russell Wilson and Justin Fields, it was initially assumed that the former would be the team's Week 1 starter. However, as the Steelers get closer to the regular season, head coach Mike Tomlin has flipped the switch on Pittsburgh's quarterback plans.

Tomlin confirmed that Wilson and Fields are in a full blown competition for QB1 duties, via Brooke Pryor of ESPN. Both player's work through the preseason will dictate Tomlin's ultimate decision.

“Very much is a competition,” Tomlin said. “What happens in stadium is weighted heavier than what happens on the practice setting because it's more game-like.”

While Fields was expected to serve as Wilson's direct backup, he now seems to have an opportunity to surpass him on the depth chart. Still, when the Steelers released their depth chart heading into their first preseason game, Wilson was listed as the starter.

But Wilson won't be playing against the Houston Texans on Friday due to a calf injury. Fields will get the start and will have ample opportunity to prove himself to Mike Tomlin. While it'll be just one preseason game, a strong impression could send Wilson into backup duties.

Not like Russell Wilson needs the preseason reps being a veteran. Arguably, Justin Fields could use more preseason time no matter of his spot on the depth chart. But performance is king for Tomlin right now, and Fields will have the first opportunity to show he can handle the starting role.

Who will win Steelers' quarterback battle? 

Chicago Bears quarterback Justin Fields (1), right, meets with Denver Broncos quarterback Russell Wilson (3) at midfield after their game at Soldier Field.
Jamie Sabau-USA TODAY Sports

While Fields may now seemingly have the upper hand, he comes to Pittsburgh with a shakier track record. He went 10-28 over his three years as a starter with the Chicago Bears, throwing for 6,674 yards, 40 touchdowns and 30 touchdowns.

But where he struggled through the air, Fields shined on the ground. He ran for 2,220 yards and 14 touchdowns, proving to be one of the best playmakers at the quarterback position. But the Steelers are looking for consistency and a leader under pocket. Fields must show massive improvement in the passing game to maintain the starting role should he earn it.

Wilson comes to town with much more experience. A 12-year NFL veteran, the quarterback is a nine-time Pro Bowler and a Super Bowl champion. He has thrown for 43,653 yards, 334 touchdowns and 106 interceptions over his career including 3,070 yards, 26 touchdowns and eight interceptions in his final year with the Denver Broncos.

However, Wilson went just 11-19 as a starter in Denver. While all of the Broncos' struggles can't be attributed to him, it was certainly a different situation than what he was used to with the Seattle Seahawks. Now on the Steelers, Wilson is looking for a second chance to prove he can still be that Pro Bowl quarterback.

But first he needs to get healthy and Wilson is losing ground to fields everyday. With Mike Tomlin confirming the pair are now entrenched in a true competition, the Steelers' Week 1 quarterback selection has become much more difficult than just choosing the veteran.