Rahne spent the 2004 season as a defensive assistant at Holy Cross, primarily working with the defensive ends. Other important roles included coordinating the scout teams, breaking down opponents' game film and assisting the defensive coordinator in developing games plans.[4] Cornell head coach Jim Knowles hired Rahne as the Big Red's running back coach in 2005.[5]
Kansas State
In 2006, Rahne served as an offensive graduate assistant at Kansas State under Head coach Ron Prince and Offensive coordinator James Franklin. Scott Frost served as a defensive graduate assistant for the Wildcats during the same period.[6] In 2007, Rahne was promoted to running backs coach where he served for two seasons. After the firing of Ron Prince, Rahne was retained by Head coach Bill Snyder as the tight ends coach, a position he would hold for the 2009 and 2010 seasons.[7]
Vanderbilt
In December 2010, Rahne was hired away from Kansas State to lead the quarterbacks for James Franklin and the Vanderbilt Commodores. At the time of the hire Kansas State head coach Bill Snyder was quoted as saying, “I am proud of Ricky, He is a fine young coach and person. His desire was to become a quarterback coach and that opportunity presented itself at Vanderbilt. I am happy for him and his wonderful family.”[8] It is a position he would hold for three successful seasons mentoring quarterbacks Jordan Rodgers and Austyn Carta-Samuels. Rodgers, under Rahne's guidance, finished 2012 season completing 60 percent of his passes for 2,539 yards, and 15 touchdowns to 5 interceptions.[9] Following the season, Rodgers would sign a free agent deal with the NFL Jacksonville Jaguars.[10]
Penn State
Following coach James Franklin, Rahne spent the 2014 and 2015 seasons as the Penn State Nittany Lions quarterbacks coach. Working with quarterback Christian Hackenberg, Rahne helped him break all of the Nittany Lions major career passing records. Hackenberg finished his career with 693 completions, 8,457 passing yards, 48 touchdown passes, 9 career 300-yard passing games, and 21 200-yard passing games.[11] After the final game of the 2015 regular season, John Donovan was fired as Penn States offensive coordinator, and replaced by Rahne as the interim to coach the TaxSlayer Bowl. During preparation for the bowl game, it was announced that ex-Fordham Head coach, Joe Moorhead would be taking over as offensive coordinator and quarterbacks coach for the 2016 season. Rahne took over as tight ends coach, a position that was previously held by Donovan.[12]
During his time as the tight ends coach Rahne mentored Mackey Award finalist Mike Gesicki as he broke the Penn State career record for receptions (123), receiving yards (1,419) and touchdowns (15) by a tight end. Gesicki was selected first-team All-Big Ten in 2017 and second team in 2016. Gesicki set single-season records at Penn State for receptions (51), receiving yards (679) and touchdown catches (9) by a tight end.[13]
On December 1, 2017, Rahne was named Penn States offensive coordinator and quarterbacks coach after Joe Moorhead left the Nittany Lions to become the head coach at Mississippi State.[14]
In 2018, Penn State saw its best rushing production in 10 years, averaging 204.9 yards per game. That was good enough to finish 29th nationally, and fifth in the Big Ten.[15] That season the offensive line was led by center Connor McGovern, who was drafted in the 3rd round of the 2019 NFL draft, and tackle Ryan Bates.[16] Junior running back Miles Sanders, who was drafted in the 2nd round of the 2019 NFL Draft, rushed for over 1,200 yards and nine touchdowns.[17] Senior quarterback Trace McSorley, who was drafted in the sixth round of the 2019 NFL Draft, passed for 2,284 yards and 16 touchdowns. He also ran for 723 yards and 11 scores.[18] Both Sanders and McSorley earned second team All-Big Ten honors.[19]
In 2019, Rahne helped lead the Nittany Lion offense to 34 points and 204.9 rushing yards per game.[20] Wide receiver K. J. Hamler, guard Steven Gonzalez and tight end Pat Freiermuth earned second team All-Big Ten honors.[21] Hamler was selected by the Denver Broncos with the 46th overall pick in the second round of the 2020 NFL draft.[22]
Old Dominion
On December 9, 2019, it was announced that Rahne had been selected as the next head football coach at Old Dominion.[23]
On August 10, 2020, Old Dominion University announced the cancellation of the football season due to the COVID-19 pandemic.[24][25]