USWNT defenders: who deserves a shot at the player pool?

Looking past Rio and its established defensive core, what does the future of the defender pool for the USWNT look like?

In its fourth season, the NWSL is a massive asset to potential members of the WNT defensive pool. Arguably defenders face the greatest struggle transitioning from college to the pro ranks. College rules with their rolling subs and lack of widespread technical acumen don't quite prepare defenders for what they'll face in the professional leagues. So making that next step can be jarring. However, the NWSL provides a domestic proving ground for defensive prospects to demonstrate they can take their game to the next level. For example, Julie Johnston parlayed a solid youth national team and college career into a Rookie of the Year NWSL season and a spot on the national team.

Modern defenders are expected to fulfill not only their expected defensive duties but also to chip in with the attack as well. Not just on set pieces where in the past defenders like Cat Whitehill have been asked to boot the ball 60 yards into the opposing 18-yard box, but outside backs are expected to bomb up and down the sidelines while central defenders are expected to be able to step into play and push up the field - the Sauerbrunn special - or contribute goals on attacking set pieces.

Arin Gilliland is the type of outside back that would fit perfectly into Jill Ellis' system. The University of Kentucky product and 2014 MAC Hermann trophy finalist was drafted by the Chicago Red Stars eighth overall in the 2015 NWSL College Draft. In her first season, Gilliland was part of a solid defensive core that conceded only 22 goals in 20 games. Her defining attributes are her pace and willingness to run up and down the sideline for a full 90. Through six games in the 2016 season, Gilliland has executed an impressive 50 possession recoveries, 33 of those being defensive recoveries. Not only does Gilliland possess pace but she utilizes that pace while remaining defensively responsible.

Gilliland's passing stats demonstrate that she is a positive, attack-minded defender. She attempts an average of 21.75 forward passes per game compared to 8.76 sideways passes and 7.57 backward passes. She's connected on 95% of her through balls in the 2016 season and 28% of her crosses. Comparatively, Ali Krieger has connected on 75% of her through balls and 25% of her crosses and Meghan Klingenberg has connected 54% of her through balls and 29% of her crosses.

Arin Gilliland Defensive Stats

Having played for the United States at the U20 and U23 level, Gilliland is a player that should be on the radar looking to the future.

Kassey Kallman and Megan Oyster are two young defenders on the rise, each with their own distinctive qualities. They haven't garnered the immediate attention out of college like Emily Sonnett but through their NWSL play have proven more than capable.

Kassey Kallman is a former ACC Defensive Player of the Year out of Florida State and someone who has been involved at the U20 and U23 levels with the United States. She was drafted fifth overall by FC Kansas City in the 2014 NWSL College Draft. In that season, she would go on to help them win their first NWSL Championship while playing left back. In that offseason Kallman was traded to the Boston Breakers where she assumed a role in the central defense.

Kallman's individual talent speaks louder than her club's poor results over the past two seasons;  the greatest obstacle to Kallman's ascendency might just be the team she plays for. Unless you look at her advanced stats the future looks pretty bleak. Boston conceded a league worst 43 goals in the 2015 season and has already conceded 11 goals in the 2016 season. Despite that, she's an incredibly intelligent defender who, through four games in 2016, has intercepted the ball 14 times. Her poise as a defender has led to her completing an astounding 97% of her passes under pressure from an opponent. Teammate Whitney Engen completed a still impressive 82% of passes under pressure but compared to Kallman that figure seems almost average.

Kassey Kallman Defensive Stats

Megan Oyster assisted on the game-winning goal that won the 2013 National Championship with UCLA. After a solid career at UCLA, she was selected 13th overall in the second round of the 2015 NWSL College Draft by the Washington Spirit. At the time this pick was regarded with some skepticism as her UCLA teammate Caprice Dydasco was rated higher than her. In good time, however, the Spirit's then-manager Mark Parsons made perfect sense with his decision. Oyster put together a rookie season that saw her considered strongly for the Rookie of the Year award. Starting every single game of the season, Oyster helped the Spirit bring their goals against down from 43 in the 2014 season to 28 in the 2015 season.

Through five games, Oyster has intercepted the ball 17 times and blocked 24 passes and shots from opponents. She's completed 80% of her passes and her confidence on the ball has her attempting only an average of 2.73 back passes per game, compared to her Canadian defensive partner, Shelina Zadorsky, who averages playing the ball back to the keeper 8.11 times per game. On set pieces she's always an aerial threat and in the 2015 season she was able to chip in a goal for the Spirit off of a set piece.

Megan Oyster Defensive Stats

A few players like WNY's Abby Dahlkemper - a versatile Mac Hermann trophy finalist - or Casey Short could be on the fringes of being able to prove themselves. Dahlkemper still needs to demonstrate that she has a best position as she has become more of a defensive and midfield Swiss army knife at the pro level. Short is starting to build an impressive resume with the Red Stars though she's prone to being overshadowed by the commanding presence of Julie Johnston and Arin Gilliland.

Regardless, the future of the United States defensive pool looks bright and that's no doubt thanks to the availability of the NWSL for these players to prove themselves domestically after college.