The Pittsburgh Steelers' championship puzzle won't be completed without a few key pieces. Here are those pieces-players that will define the upcoming season for the Steelers. Returning to the Super Bowl is a must, but it will not come without these players owning in the league.

Mike Wallace

Wallace just ended an extended holdout for the Steelers. He needs the team just as much as the Steelers need him. Wallace is playing for his "Larry Fitzgerald money" and will do anything to shine as such. He's out to prove he is a top receiver and will ball out this year to at least earn himself the franchise tag. Over his 3 years with the team, Wallace has averaged over 1,060yards a year with eight touchdowns. If Big Ben stays healthy, expect an air show this year with the determined Wallace.

Antonio Brown

Brown has already accomplished something Wallace has not, which is getting the bigpayday. With only one accomplished season under his belt,he has shown the Steelers enough to make him one of Ben Roethlisberger's favorite targets. Brown and Wallace will form one of the most formidable WR duos in the game. And remember, Antonio Brown is not just a wide receiver-he can be a game changer if given the opportunity in the return game as well.

Rashard Mendenhall

If Mendenhall returned to his 2010 form, it would be the ideal situation for the Steelers.Since he is returning from reconstructive knee surgery, though, they will obviously lighten the load. Whether Mendenhall will start Game 1 or miss time is still a mystery, but he will be needed and leaned on as the season continues. Stats from last year show he lacked the proper amount of carries. In the four games the Steelers lost, Mendenhall carried the ball 15 times or less. Pittsburgh needs to return to the grind it out football for their domination the AFC North to return.

Keenan Lewis

Lewis is a 4th year pro, but only has one career start under his belt. Because of that, he will be under the spotlight this season. While he will have the help of the front seven, with a large portion of pass rush coming from James Harrison, most offensive coordinators will highlight Lewis as a target. He will rise to the occasion and prove the doubters wrong showing he belongs on the Steelers defense. Lewis's greatest challenge with come in the form of theGiants (Victor Cruz and Hakeem Nicks), Ravens (Torrey Smith and Anquan Boldin),and Cowboys (Miles Austin and Dez Bryant). These are the key games in which Lewis' performance will define his season.