In 2008, Rehring began his playing career with his alma mater, Franklin & Marshall, following his graduation.
[6] In 2018, Rehring was named as the NCAA Division III's AFCA Assistant Coach of the Year.
[7] On February 25, 2019, Rehring was named the head football coach for the State University of New York Maritime College.
[12] In his inaugural season he led the team to a 5–6 record and finished second in the Eastern Collegiate Football Conference (ECFC).
[13] Due to Dean in the process of transitioning to the Division III level, Maritime was selected as the ECFC's qualifier for the playoffs.
In 2023, Maritime went 5–5 and 3–4 in New England Women's and Men's Athletic (NEWMAC) play which finished in tied-fourth place.
[23] They beat Coast Guard 24–21 on homecoming before losing the final two games of the season to Salve Regina 49–0 and Springfield 51–6.