The Pittsburgh Steelers are trying to pull off a massive upset Sunday night against the Kansas City Chiefs. They are double-digit underdogs and will need all their key contributors to stand a chance.The team received some exciting news earlier in the week. They learned that JuJu Smith-Schuster can practice again and is expected to play Sunday. They also got more clarity on another player -- running back Najee Harris.Adam Schefter@AdamSchefterSteelers are removing RB Najee Harris from the injury/status report with his elbow injury, and he is expected to play Sunday night vs. the Chiefs.12:51 PM · Jan 15, 20224207244Steelers are removing RB Najee Harris from the injury/status report with his elbow injury, and he is expected to play Sunday night vs. the Chiefs.Harris was dealing with an elbow injury and was limited to 28 rushing yards in Week 18 against the Baltimore Ravens. His return, along with that of Smith-Schuster, is an enormous boost to the Pittsburgh offense ahead of such a big game.Steelers get fantastic news on Najee HarrisPittsburgh Steelers v Baltimore RavensHarris has been a focal point on offense for the Steelers as a rookie. He rushed for 1,200 yards and seven touchdowns, and added 467 yards and three touchdowns as a receiver.The running back being healthy is a major key because he has been a crutch for Ben Roethlisberger on offense all season. He has the third-most receptions on the team with 74, for an average of 6.4 yards per reception. Roethlisberger can always find Harris to bail himself out, if no one else is open downfield.Then, there is Harris' obvious dominance in the running game. He ran the ball 307 times for 1,200 yards. No one else on the team even reached 100 yards on the ground. Benny Snell Jr. was next closest in attempts with 36. The rookie Harris was available all season and was relied upon each and every drive.The Steelers are already entering the game trying to do the impossible. Harris and Smith-Schuster being back only increases their chances of success and gives Roethlisberger two reliable targets. Both players are great at getting open a few yards down the field.Bradley Locker@Bradley_LockerNajee Harris' rookie season:307 carries1,200 rushing yards7 rushing touchdowns74 receptions467 receiving yards3 receiving touchdowns0 fumblesHe's one of two rookies to EVER have 1,650+ scrimmage yards and not fumble, joining Saquon Barkley in 2018.A is born.9:28 AM · Jan 9, 20225971709Najee Harris' rookie season:307 carries1,200 rushing yards7 rushing touchdowns74 receptions467 receiving yards3 receiving touchdowns0 fumblesHe's one of two rookies to EVER have 1,650+ scrimmage yards and not fumble, joining Saquon Barkley in 2018.A 🌟 is born. https://t.co/ZrgWiI3oP6No matter what happens Sunday, Harris has proven he can be a star on the offense for years to come. He may not have the same dynamic abilities as a Le'Veon Bell, but he is putting up the yards and proving to be a reliable option week in and week out.A big game against the Chiefs would make him a Pittsburgh legend in only his first NFL season.Also check out: Tampa Bay Buccaneers Playoff History, Appearances, Wins and more