Denver’s national championship aspirations took a hit Tuesday, as coach Bill Tierney announced that standout long-stick midfielder Sean Mayle will miss the remainder of the season after the school and the NCAA deemed him academically ineligible.

“Because of the University of Denver’s unique academic quarter system, we have to monitor our academic success twice during the regular season,” Tierney said. “Due to a technicality with a course that Sean repeated and passed, the school and NCAA have deemed him ineligible. Not having No. 6 on the field is a huge loss for our program, especially in light of our potential playoff run, but all appeals have been exhausted.

“It’s time to move forward and for our defense to continue to play at a high level, as they have the last five games,” Tierney added. “Sean is one of the absolute finest young men, players and leaders that I have ever had in my career, and we will continue to support him toward graduation and enthusiastically cheer him on in his professional career.”

Mayle was the No. 6 overall pick in the Major League Lacrosse draft and will join the Chesapeake Bayhawks after the NCAA season.

Traditionally known for its efficient and productive offense, Denver has won seven straight games and tore through the Big East portion of its schedule with a stifling defense. The Pioneers rank first in scoring defense in Division I, yielding just 7.46 goals per game. Although Mayle played a significant role in the unit — while also manning the wings on faceoffs and scoring five goals in the eight games he played this season — the Denver defense has not missed a beat since he last appeared in a game March 24 against Towson. The Pioneers have allowed just 6.6 goals per game in the five games since then.

Denver (11-2), ranked fourth in the latest Nike/US Lacrosse Division I Men’s Top 20, will open postseason play Thursday against Marquette in the Big East semifinals at Villanova.