When the Chicago Bears picked center Hroniss Grasu out of Oregon in the third-round of this year's draft, the rookie was not ready to start in the NFL. He weighed in the low 290s and had to pack on a few pounds in order to hold his own at the next level.

The Bears have helped Grasu get up to about 305 pounds, according to Rich Campbell of the Chicago Tribune. With starting center Will Montgomery placed on injured reserve this week, a bulkier Grasu may get his first chance to start on Sunday against the Kansas City Chiefs.

"If my number gets called, I feel like I can step right in and help these guys out," Grasu said, per the Chicago Tribune. "But I know mistakes will happen. … You just have to get better from it."

More from FoxSports

Last week, when Montgomery was injured, Matt Slauson bumped over to center and reserve offensive lineman Patrick Omameh filled in at left guard (Grasu was inactive). Omameh is dealing with an ankle injury this week, so the Bears may turn to their third-round rookie in Week 5.

MORE NEWS: Want stories delivered to you? Sign up for our NFL newsletters.