2013 (Crew): Withrow did not make a regular-season appearance in his rookie season with the Crew after signing with team on March 7, 2013. He missed matches against Houston (June 1) and at Philadelphia (June 5) with a right foot injury. He served as the primary back-up in the match against Portland (July 7) before making his professional debut in the international friendly against Wigan Athletic (July 13) where he conceded a goal in 40 minutes of action. Withrow became the primary back-up to starter Matt Lampson when Andy Gruenebaum missed time due to a left shoulder injury for eight matches from August 3-September 14 before suffering a concussion ahead in training that would cause him to miss matches against Chicago (September 21) and at FC Dallas (September 29). He posted a record of 2-1-0 with a 1.00 goals against average in three appearances – all starts – in 2013 MLS Reserve League play.
Withrow played collegiately at Marshall University. As a senior, started 17 games, only allowing nine goals. The netminder also posted a 0.52 goals against average, 11 wins and nine shutouts. He earned NCAA All-Midwest Region and All-Conference USA honors after being named the program's first Co-Conference USA Player of the Year. As a junior, Withrow recorded four shutouts on the year in 16 starts. He led C-USA in saves with 79 and in saves-per-game (4.94) as a junior. That year, Withrow also provided the game-winning assist to Tom Jackson in the Herd's 3-0 win over Memphis. He was named to the All-Conference USA First Team for the second year in a row, and was the only goalkeeper elected to the C-USA First Team. As a sophomore, in 18 starts, Withrow played every minute of the season in net for the Herd to record 65 saves and had five shutout wins and a 1.04 goals against average. He earned Conference USA Defender of the Year, First-Team All-Conference USA and Second Team All-Midwest Region selections as well as a sophomore. As a redshirt freshman in 2009, Withrow played in 16 games, started 14, and logged 1391 minutes in net to register 65 saves with a 1.10 goals against average and a .793 saves percentage. He recorded one goal and one assist on the season and was named the Conference USA Defensive Player of the Week on September 21 and earned a Soccer America National Team of the Week selection that same week. Withrow was named Conference USA Freshman of the Year, All Conference USA Second-Team selection and Conference USA All-Freshman Team at the end of his freshman season.
Withrow attended high school at Rochester Adams and played for coach Juan Delgado. He recorded 27 shutouts during a three-year campaign and was selected all-league two different years. Withrow was also a two-time all-county, all-district, all-region and all-state member in 2006 and 2007. He guided Rochester to a league championship in 2006 and 2007, and the 2006 district championships. He was named the 2007 team MVP and captain.