Aynsley Rosenbaum begins his second season on the Merrimack College football coach staff in 2022. Rosenbaum works directly with the team's wide receivers. 

In his first season guiding the wide receivers, he coached Jacari Carter to one of the most prolific seasons in program history. Carter was named an FCS Freshman All-American after he had 89 receptions in 11 games with 713 yards and eight touchdowns. He also earned first team All-NEC honors after the season and was a finalist for the Jerry Rice award as the nation's top FCS freshman. 

Rosenbaum came to Merrimack after 13 years at Framingham State University. He was named the Head Football Coach on January 19, 2020 after 12 seasons as the offensive coordinator. Although he was unable to be on the sideline as head coach, he guided the team through a cancelled 2020 season of training and practice.  He was also the school's Assistant Director of Athletics overseeing Club Sports and Recruiting.

During Rosenbaum’s 12 seasons on the sideline the Rams won nine conference championships, made five appearances in the NCAA Division III Football Tournament and won four bowl games. During that time, Rosenbaum's offenses rewrote Framingham's record book.

Rosenbaum’s offenses led the MASCAC in points (2019, 2018, 2017, 2016, 2015), rushing (2019, 2017), rushing touchdowns (2018, 2017, 2016), total offense (2019, 2017, 2014, 2013) and passing touchdowns (2019, 2014).  Rosenbaum’s offenses featured the University’s first four single season 1,000 yard rushers and first single season 1,000 yard receiver. His offenses featured three conference Offensive Players of the Year, five Offensive Lineman of the Year and four conference Offensive Rookies of the Year.

In 2013 Rosenbaum was honored by the Gridiron Club of Greater Boston as the Division II/III Assistant Coach of the Year.

Rosenbaum has coached 33 first team All-Conference players and 19 second team selections.  Eleven players on the offensive side of the ball were selected to the New England Football Writer’s Division II/III All-New England Team during his tenure. He has also coached ten D3football.com All-Region selections. He has guided the offense that featured a two-time D3football.com All-America selection as well as three Joseph P. Zabilski Award winners. 

Before coaching at Framingham, Rosenbaum spent seven seasons with the Arlington Catholic High School football program where they won three Catholic Central Titles and made two trips to the postseason.  At Arlington Catholic Rosenbaum coached three All-Scholastic quarterbacks and two All-State receivers.

As a player, Rosenbaum was a running back and kick return man for Framingham State from 1995-97.  He led the team in rushing in 1995 and 1996, while also averaging 19.3 yards per return during his career. 

Rosenbaum currently resides in Andover with his wife Melissa and two daughters Mia & Layne.