For the second consecutive year, John Cena is not in the WWE World Heavyweight Title picture heading into WrestleMania. The 15-time world champion will face Rusev for the United States Championship at WrestleMania 31 in a match that has all but been made official.

Cena is looking for a rematch with Rusev after losing his U.S. Title match at WWE Fast Lane. In the build towards the match, the undefeated Rusev has talked about Cena being “old” and past his prime, something that has reportedly caused a stir backstage.

While Rusev’s portrayal of Cena is just part of the storyline, Cena’s role in WWE does appear to be changing.  Having spent a decade as WWE’s biggest star, the 37-year-old is no longer in the same position he was in a few years ago.

Fans need to look no further than Cena’s WrestleMania history to see his changing role within the company. From 2005 to 2013, Cena didn’t fight for the WWE Title or World Heavyweight Championship on just one WrestleMania card. The one exception came at WrestleMania 28 when he faced The Rock in the most high-profile match of his career.

In the last two years, he’s faced up-and-coming superstars in their first ever WrestleMania matches. In 2014, Cena defeated Bray Wyatt in a non-title match. On March 29, he’ll have a match with Rusev for WWE’s No.3 singles title.

Roman Reigns will challenge Brock Lesnar for the WWE World Heavyweight Championship in the main event of WrestleMania 31. The former Shield member is expected to become the champ, as WWE grooms him to be the next face of the company.

But Cena’s placement on the card isn’t because of a decrease in popularity. He has become such a big star that any match he’s in becomes one of the biggest matches on the card. The United States championship will receive a level of importance that it hasn’t seen in years by having Cena fight for the belt.

Even though Cena defeated Wyatt at WrestleMania 30, simply working with the face of WWE has helped elevate the 27-year-old. A year after losing to Cena, Wyatt will meet The Undertaker on the Grandest Stage of Them All.

Cena’s role may be changing, and WWE is looking to build new stars, but that doesn’t mean Cena won’t hold the company's most-coveted title again. He won the belt in June after an injury forced Daniel Bryan to give up the championship, and WWE could re-insert him into the title picture at a moment’s notice.   

Bryan still gets the loudest pops on the roster, but Cena is unquestionably the company’s No.1 star. Whether he’s being booed or cheered, he always draws a response from the crowd. He still leads the company in merchandise sales and is showing no signs of slowing down.

It’s been nearly 13 years since his WWE debut, but there’s still a lot Cena can do in WWE. He’s been a babyface throughout his decade-long run as a main eventer, and though some believe he’ll never turn heel, there might come a time when Cena makes his way over to the dark side.

It might not happen in 2015, but history indicates that Cena will get a run as a heel. Spending more than a decade as the most popular wrestler in the world, Hulk Hogan eventually turned heel and joined the NWO. Brett Hart did the same a year later, having spent his years at the top of WWE as a babyface.  

Set to turn 38 years old less than a month after WrestleMania 31, Cena is older than most of WWE’s full-time wrestlers. But he’s still able to deliver some of the year’s best matches, despite being perceived by some as a below-average worker. Not only was his match with Rusev arguably the best on the Fast Lane card, but his triple threat match with Lesnar and Seth Rollins at the 2015 Royal Rumble was one of the best WWE matches in recent memory.

Cena won’t be on top forever, and it wouldn’t behoove WWE for that to be the case. The company needs superstars like Reigns, Rollins, Rusev, Wyatt and Dean Ambrose to take the next step as main event wrestlers. 

At Levi’s Stadium, Cena will fight for the mid-card championship that he won in his WrestleMania debut 11 years ago. But it will come as no surprise if he ties Ric Flair’s record for 16 world title runs before the end of the year.