Travis Swanson reportedly undergoes shoulder surgery

Lost under the heap of all the Bob Quinn news dropped on Friday was a small report regarding Detroit Lions center Travis Swanson. According to Ian Rapoport, Swanson has already undergone surgery for his shoulder injury:

#Lions center Travis Swanson had successful shoulder surgery last week, source said. He was plagued with the injury all season long

— Ian Rapoport (@RapSheet) January 15, 2016

Swanson's surgery comes as no surprise, as his shoulder injury held him out of the season finale and pushed him to the injured reserve list for the final week of the season.

However, the report that this injury nagged at Swanson all season is the more interesting piece of news. Though Swanson battled an ankle injury earlier in the year, his shoulder injury didn't show up on any reports until Week 17.

If Swanson did truly struggle all year with this ailment, it would provide an explanation to his poor play in 2015. Swanson consistently found himself on the "Worst Grades" list in our weekly Pro Football Focus ratings roundups despite high hopes for him entering his first season as a full-time starter.