Ask how, ask now, ask Kerwynn Williams.
The Arizona Cardinals running back who was recently snagged up off the practice squad rattled the cages a little bit in Week 14 against the Kansas City Chiefs. By end of the game, a new potential fantasy option for Week 15 had bloomed. Williams wound up with 19 carries for 100 yards in his first real NFL action, but a matchup against what has become one of the best defenses in the NFL in addition to the fact that Williams benefited from some situations the Cardinals don't usually find themselves in under quarterback Drew Stanton make Williams a risky option in Week 15.
How he succeeded against Kansas City
In his second NFL game, Williams got his first opportunity to carry the ball and didn't disappoint. He displayed good burst out of the backfield, showing the ability to get up into second gear a little bit quicker than his teammates Stepfan Taylor and Marion Grice. If you watched that game and noticed the wealth of carries being spread around the Cardinals' backfield between Taylor, Grice and Williams, you figured Williams would ultimately wind up unstartable due to the backfield being so crowded.
But Williams shifted that notion more into his favor during the second half. Granted, his fantasy stats benefited from some game flow luck as the Cardinals found themselves surprisingly ahead after quarterback Drew Stanton connected with Jaron Brown on a seam route for a 17-14 go-ahead touchdown. When the Chiefs failed to respond with a score of their own on the next series, it allowed the Cardinals to serve the Chiefs heavy doses of their run game with Williams as the focal point.
Which leads to a major concern you should acknowledge if you're starting Williams against St. Louis this week. The Cardinals haven't gotten out to early leads with Drew Stanton at quarterback. Since former starter Carson Palmer tore his ACL in Week 10, the Cardinals have failed to score the first touchdown in three out of four games with Stanton under center.
And that's the thing with game flow. The majority of Williams' carries came in that second half when the Cardinals were ahead and needed to run the clock down. His confidence grew as the game went along, and for Bruce Arians and the coaching staff to rely on him in a game where the Cardinals most surely had to win with the Seahawks breathing down their neck is a good sign for Williams' value going forward. But even though Williams played well, he still only played in 36 percent of the Cardinals' offensive snaps while Stepfan Taylor was on the field for 25 percent of snaps. It's promising, but not incredibly promising.
Williams was drafted by the Indianapolis Colts in the seventh round of the 2013 draft. After spending some time on practice squads in Indy and later San Diego, Williams found himself without a team until the Cardinals signed him shortly after the 2014 season began.
Coming out of Utah State, Williams rushed for 1,512 yards and 15 touchdowns as a senior (6.9 yards per carry). He also set the single season record for receiving yards in (697) by a running back in 2012.
At 5'8, 198 pounds, Williams is an undersized running back who uses his explosiveness to create positive yardage fast. As you watch him in this clip, he does possess the home run ability in the open field. He measured at 4.48 40 speed at the combine in 2013 to go along with a 35" vertical. He's got good lateral ability and can zig zag along the offensive line at a good pace until he finds a crease. His undersized nature benefits him as it makes him tough to tackle and thus slippery, but it does limit him when it comes to plowing through defenders.
The Rams defense
if you consider starting Williams against the Rams on Thursday, you're doing so at a big risk. The Rams defense arguably improved the most as the season went along. They've climbed to sixth best against fantasy running backs after struggling early on. They now allow just under 13 points per game from RBs. They're also coming off consecutive shutouts against Washington and Oakland.
They held Alfred Morris, a decent running back in his own right, to just six yards on eight carries last week. They allowed Raiders running back Darren McFadden (I know, it's McFadden) to just 27 yards on 11 carries a week before. The last time they allowed a 100 yard rusher was three games back against Chargers' Ryan Mathews.
The return of defensive end Chris Long has really given the Rams an extra pass rusher to go along with Robert Quinn. Both defensive ends have played well in recent games, with each accounting for a sack in the last two contests. Linebacker Alec Ogletree has played better against the run recently after struggling early and their two safeties in Rodney McLeod and Mark Barron have been arguably the best combination at their respective positions in the league since Barron came over from Tampa Bay in late October.
If you picked up Kerwynn Williams, you have no reason to start him in this matchup. Steer clear if possible.