The Top 25 Under 25 is a collaboration by Mile High Hockey staff members. Six writers have ranked players under the age of 25 in the Colorado Avalanche organization as of September 1, 2025. Now, we’ll count down each of the 25 players ranked (plus one Honorable Mention).
Coming in at number five on our Top 25 Under 25, holding steady despite an entire missed year, is defenseman Sean Behrens. One of this organization’s most lauded youthful defenders, he finally received an opportunity during the prior season…almost.
Behrens is an offensive defenseman who is great at moving the puck. Prior to the unfortunate last season (which we will discuss in a moment), he spent three seasons at the University of Denver. There he would help the Pioneers win two championships in three seasons. Behrens would win several awards while attending DU, which included the NCHC All-Rookie Team and NCHC Defenseman of the Year. All this was after the Colorado Avalanche had drafted Behrens in the second round of the 2021 draft.
Behrens, despite being small in stature, did not let that stop him during his collegiate career. He was recognized equally for delivering blows as for enduring them. In 112 contests with the Pioneers, Behrens finished with 10 goals and 71 assists. The eye-popping stat for him was his plus-45 before deciding to turn pro.
After his junior year with DU, Behrens decided it was time to turn pro and signed his entry-level contract with the Avalanche. Colorado immediately assigned him to the AHL Colorado Eagles on an amateur tryout agreement. It did not take long for Behrens to get comfortable at the professional level during his pro debut on April 20, 2024. He would help on a Peter Holland goal to tally his first point.
During training camp last fall, Behrens was fighting for a puck in the corner during a scrimmage and tore his ACL. It forced him to miss the entire season for the Eagles (72 regular season and nine playoff games). He stayed with the Eagles and rehab his knee and began skating right before the playoffs ended.
The Barrington, Illinois, native will be a key part of the Eagles’ defensive core this upcoming season. He unfortunately has not played in any games since April 26, 2024, so there may be an adjustment period for the American. If the Avalanche’s blue line suffers injuries, Behrens might finally debut in the NHL this season.