Heading into this week's matchup with the Pittsburgh Steelers, the Indianapolis Colts are still flying under the radar to the rest of the NFL. Even with Andrew Luck giving the Colts late notice that he was retiring just before the start of the season, the teams has rallied behind Jacoby Brissett and are looking like legitimate contenders in the AFC.

While the Steelers were just recently considered Super Bowl contenders themselves, they have fallen off incredibly quickly.

Le'Veon Bell is gone to the New York Jets after leaving this offseason in free agency. Antonio Brown forced his way out of Pittsburgh and has gone through a nightmare since that move was made. Finally, Ben Roethlisberger saw his season end prematurely due to a an injury.

Indianapolis, on the other hand, has a 5-2 record entering this week. There may be some that don't want to call them title contenders yet, but they are well on their way to earning that recognition. In order to stay on top of the AFC South division, the Colts will need to pick up a win this week.

All of that being said, let's dive in and take a look at four reasons why the Colts will defeat the Steelers this week.

4. Mason Rudolph Isn't A Game-Changer Yet

When Roethlisberger went down for the Steelers, there was a lot of pressure on Pittsburgh to make a move to bring in a veteran quarterback. Instead, they decided to stick with Mason Rudolph and see what they had for the future. While the talent is there, Rudolph isn't ready to be a game-changer just yet.

So far this season in five games, Rudolph has completed 63.8 percent of his pass attempts for 897 yards, nine touchdowns, and three interceptions. He has shown major promise of being a franchise quarterback. Maybe he will even make it a tough decision between himself and Big Ben next year.

3. Marlon Mack Will Continue His Impressive Season

One of the main focal points for the Colts this season has been getting Marlon Mack going. They have been able to accomplish that goal and then some.

On the season, Mack has carried the football 138 times for 590 yards and three touchdowns. He has also caught 11 passes for 68 yards. There is still plenty of room for Mack to grow, but he has become a lethal threat for opposing defenses to plan against.

2. Eric Ebron Is In For A Massive Breakout Week

Indianapolis has not had many negatives this season, but the play of Eric Ebron has been one of them. He put together a career season last year for the Colts and was expected to do so again this year. That simply has not been the case.

Unfortunately for the Colts, Ebron is going to have to be asked to pick up some slack this week. T.Y. Hilton will miss this week's matchup with the Steelers and could be out a month with a calf injury. Ebron may not be the only guy that sees his targets rise dramatically, but he certainly is going to be utilized much more this week.

1. Jacoby Brissett Has Quickly Turned Into A Legitimate Franchise QB

Finally, the Colts could not be happier to move on from one star quarterback to another. Jacoby Brissett still has some work to do to become one of the top quarterbacks in the game, but he has the arm and potential to do just that.

Brissett has completed 64.5 percent of his pass attempts for 1,590 yards, 14 touchdowns, and three interceptions. His production has made the loss of Andrew Luck seem unimportant for most of the year. If the Colts continue getting the production they have come know and love from Brissett, they should be able to walk out of this one with a fairly convincing win.