Minnesota Vikings center John Sullivan lost his entire 2015 season to a back injury suffered in the preseason. He took over the starting center spot for the Vikings in 2009, and prior to last season had started 93 of 96 possible regular season games and three post-season contests for the Vikings. He had to sit back and watch his replacement, Joe Berger, put together an outstanding season in his place in 2015, and has really gotten himself ready for 2016.

According to Chris Tomasson of the St. Paul Pioneer Press, Sullivan has lost around 20 pounds this offseason, thanks in large part to refining his diet and working with new strength/conditioning coach Brent Salazar.

"I'm cognizant of what I eat at all times," Sullivan said. "I don't have cheat meals. ... Just working out with Brent and his program is excellent. He does a really good job of focusing on muscle activation. ... I feel like I'm moving well when I get on the field. I don't even think about my injuries from a year ago, so I'm really feeling good."

Sullivan has played his career with the Vikings at a weight between 320 and 325 pounds, but is now down closer to the 300-pound mark. Sullivan says that he made the change to decrease the level of stress on his back.

Sullivan is under contract to the Vikings through the 2017 season, but thanks to an extension he signed back in 2014, if the Vikings chose to part ways with him, they could do so with a very minimal salary cap hit. The battle between him and Berger for the center spot in Minnesota is going to be just one of the stories along the offensive line in Training Camp, and one of many battles that will make the o-line the most interesting position to watch when Training Camp gets underway in late July.

Do you think that John Sullivan can supplant Joe Berger at the center spot after missing all of 2015?