PITTSBURGH — Andrew Luck understands weekly comparisons between himself and the opposing quarterback, even if the Indianapolis Colts star doesn’t quite get it.

“It’s always weird talking about playing the other quarterback because you don’t (play them), you never do,” Luck said. “You play the defense.”

Or toy with the defense, in Luck’s case.

The former No. 1 pick’s 19 touchdown passes are tied for the NFL lead along with predecessor Peyton Manning. Luck has topped 300 yards in each of the last five weeks, a streak that happens to coincide with the five-game winning streak the Colts (5-2) carry into Sunday’s game against Ben Roethlisberger and the erratic Pittsburgh Steelers (4-3).

In his third season, Luck is becoming very much his own man. He’s no longer simply the son of a former NFL quarterback, the appointed successor to Manning or the guy the Colts opted for instead of Robert Griffin III.

“He’s his own unique animal,” Steelers coach Mike Tomlin said.

One that is still in the early stages of a prime that could dominant the league for the next decade. Yet while the contrast between Luck and Manning is natural considering the circumstances, the link between Luck and Roethlisberger might be more apt.

Like Roethlisberger, Luck has the arm strength to stand in the pocket amid heavy pressure, but also the mobility to break loose and make things up as he goes. Like Roethlisberger and Manning, Luck honed his craft under the guidance of Bruce Arians, who served as an assistant with the Steelers and Colts, even briefly taking over as interim head coach in Indianapolis while Chuck Pagano dealt with leukemia.

Arians, who won the AP Coach of the Year Award in 2012 for his fill-in stint, made Luck watch tape of Roethlisberger finding order amid chaos, an attribute Luck is still trying to master.

“His ability to extend plays is incredible, maybe the best in the league (with) what he does in finding an open guy if something breaks down,” Luck said.

Stylistic similarities aside, Luck and Roethlisberger meet with their teams at different points in their development. Indianapolis has shaken off an 0-2 start with ease and its 27-0 romp over Cincinnati last week was one of the most impressive victories of the season.

The Steelers are an enigma as they reach the midway point, flip-flopping from explosive to inconsistent week to week. Pittsburgh has alternated wins and losses through seven games. Not exactly the way to end a two-year playoff drought.

“We make some mistakes at times,” Roethlisberger said. “We show flashes of being a good team, but it’s still early enough in the season that we can make some corrections and adjustments and just try and play good football when it matters.”

Other things to look for as the Colts search for their first six-game winning streak since 2009:

REUNITED: Steelers wide receiver Antonio Brown and Indianapolis WR T.Y. Hilton grew up together in Florida, providing their youth football team with a ridiculously speedy one-two combination. They’ll face each other for the first time as pros on Sunday. They’ve become vital parts of potent offenses.

Brown leads the NFL with 719 yards receiving, though Hilton is right behind Brown with 711.

“They’ve got feet like a shore bird,” Pagano said.