CardinalsSource.com analysis: What makes Johnson such a valuable asset to Arizona's offense? There's no shortage of traits that Johnson possesses that most NFL backs would kill to acquire, but perhaps his best quality is his versatility. In an era where backs are increasingly specialized and rotated based on situations, Johnson is the rare player who excels at all aspects of the running back role, which is why he's so tough for defenses to defend. At 6-foot-1 and 224 pounds, Johnson has the size to burst through the line of scrimmage on short yardage situations, but he also has the speed to break away from defenders at the second level and outrun his competition down the field. After nabbing 80 receptions a season ago, Johnson also proved he was the best pass-catching running back in the league, which allows the Cardinals to split him out wide and create mismatches against safeties and linebackers. Additionally, Johnson is also the best blocking back on the Cardinals' roster, as he's fundamentally sound and creates a wide base that's difficult for opponents to displace upon contact. Head coach Bruce Arians was outspoken at various points last season, suggesting he's harder on Johnson than the rest of his players because he has such a high ceiling. Even after some of Johnson's best games, Arians offered corrections for him and indicated Johnson often left yards out on the field. If there's more untapped potential inside of Johnson, it's going to create issues for the rest of the NFL, because he's already well on his way to becoming one of the most dominant players in the sport.
CardinalsSource.com analysis: Though Williams is only 5-foot-8 and 198 pounds, he showcased tremendous short-area quickness and great elusiveness last season when given the opportunity to fill in behind Johnson. The Cardinals primarily used Williams out of a Wildcat set, but he has the skill set and the speed necessary to help the team in shotgun formations because it doesn't take long for Williams to get up to full speed and because he hits the hole at the line of scrimmage with his legs churning. Williams isn't the type of back who's going to drag tacklers and he has yet to establish himself as an asset in the passing game as a blocker or as a receiver, so there are some limitations to what he brings to the table which is why he's found it challenging to stick on the team's active roster for an extended period of time. Nevertheless, Williams and the Cardinals turned a corner last season, as the team was hungry for secondary production behind Johnson and found it in the form of Williams. Even if he only gives the Cardinals 10-to-15 offensive snaps a game, there's value in putting Williams in the backfield and giving Johnson a breather, or splitting Johnson out wide. The Cardinals have talked in the offseason about adding a backup tailback who has the same type of skill set as Johnson, but we think Arizona may be best served by using Williams as a complementary piece who brings a change of pace to the table.
CardinalsSource.com analysis: CardinalsSource is particularly high on Penny given the fact the Cardinals don't have a big-bodied tailback on the team's 90-man roster. There are creative ways Arizona could deploy Penny due to his combination of size and strength, and we think he'd make an excellent goal line or short yardage back for a team that is bound to overuse David Johnson at some point this season. What we like most about Penny is that he's a relatively fluid mover for his size, and he's durable enough to absorb contact and keep his legs running. Even though Penny was playing against lesser competition in the fourth week of the preseason last year, we thought he made a convincing case for a roster spot because he proved he was capable of being a full-service back who could specialize in certain situations that play to his strengths. If Penny doesn't earn a spot on the Cardinals' roster this season, it wouldn't surprise us if he bolted for an opportunity on another 53-man roster or to a practice squad where he would need to overcome less to earn a promotion. The presence of Johnson makes it hard for the Cardinals to consider giving more opportunities to other backs, but we were intrigued by what Penny had to offer last fall and we're eager to see how he's developed when the Cardinals get on the field in fall camp.
4. T.J. Logan
CardinalsSource.com analysis: There aren't many teams Logan could have gone to in the NFL that would have been a better schematic and stylistic fit than the Arizona Cardinals, an organization that prioritizes speed and is seemingly doing everything in its power to put as many skill position players who run sub 4.4 40-yard dash times on the field at once. Logan will make Arizona better as a rookie, because regardless of how he contributes on the offensive side of the ball, there will be ample opportunities for him to impact the game as a special teams contributor, an area where the Cardinals were dismal in 2016. On offense, though, Logan could see early playing time if the Cardinals are convinced they can use his speed as an asset when Johnson needs a breather. Perhaps Logan finds himself in the third or fourth spot on the depth chart, or perhaps the Cardinals use him as Johnson's primary backup, but Arians will come to know which types of plays are best for Logan and he'll likely attempt to put him in advantageous situations as much as possible. Logan isn't going to be the Cardinals' third and short back, but he can help the team in early down situations, and especially when Arizona wants to run the ball out of shotgun sets.
CardinalsSource.com analysis: Though CardinalsSource hasn't had an opportunity to evaluate Summers in person yet, he's got a tough road to make the team's 53-man roster because Arizona is already high on the backs ahead of him and he's still learning the nuances of the position. Summers was a quarterback at the junior college level at Hinds College, and didn't earn a high volume of reps at the running back position until last year. When we turn on Summers' film, he has a decent initial burst and keeps his legs churning upon contact, but he runs with a high pad level which isn't atypical of players who attempt to transition away from the quarterback position to another skill position role. At this point in his development, Summers is more of an athlete attempting to play running back as opposed to a running back with great athleticism, and that could make his push for a roster spot a significant challenge. The best case scenario in our estimation for Summers is to spend the season on the Cardinals' practice squad, learning from the likes of Freddie Kitchens and new assistant coach Terry Allen who can continue to help mold him into a more complete tailback.