Fantasy football start/sit advice, Week 10: Trent Richardson/Donald Brown

It's been a disastrous season for Indianapolis Colts running back Trent Richardson, acquired by the team after Week 2 for a first-round draft pick. Behind him, backup running back Donald Brown has been far more impressive. Sunday, both running backs hope to take advantage of a porous run defense as the team takes on the St. Louis Rams.

With the Colts, Richardson has rushed for 248 yards on 83 carries, for a yards-per-carry average of less than 3.0. Meanwhile, his backup, Brown, has nearly as many yards — 244 — on only 39 carries in limited time this year, an average of 6.3 yards a carry. Richardson has two touchdowns with the Colts, one each in his first two games with the team, while Brown's lone score came in the team's Week 5 win against the Seattle Seahawks.

Fantasy impact: Richardson has been an abject disaster with Indianapolis. His first score came in a "let's welcome the new guy" situation, while his second came against the Jacksonville Jaguars. Neither heralded good things ahead for the former first-round pick. Meanwhile, Brown, who was the team's fourth option this year behind Richardson and the now-injured Vick Ballard and Ahmad Bradshaw, has easily been the most impressive running back, albeit in not many carries.

The good news for both backs, and for the Colts at large, is their Sunday opponent, the St. Louis Rams, have been the fourth-worst team in the NFL against opposing running backs this season, giving up 20.9 points a game. Just a week ago, the Rams allowed 170 total yards and two touchdowns to Tennessee Titans running back Chris Johnson.