Chargers running back Ryan Mathews already has a solid performance against his Week 15 opponent -- he scored 11 Fantasy points (in standard leagues) on 59 rushing yards and a touchdown against the Broncos in Week 10.
Since that game, Mathews has run for over 100 yards twice, scoring two touchdowns and averaging 22.3 receiving yards. In that four-game span, Mathews has averaged 13.3 Fantasy points per game in standard leagues.
Denver, meanwhile, has allowed five touchdowns over those last four games to opposing running backs, as well as 41 receiving yards per game. They've caused four fumbles in that run, which might be a bit of a concern for Mathews, who has encountered fumble issues in the past, but Mathews has fumbled just once this season and could carry momentum forward from his 29-carry game in Week 14.
There's still some risk involved with Mathews -- a quick turnaround after a heavy workload, the presence of Danny Woodhead, and the past fumble issues -- but he's solid enough of an option to be used in most Fantasy formats this week.