Las, Vegas, Nevada - University of Nevada, Las Vegas (UNLV) football is mourning the loss of defensive lineman Ryan Keeler, who died on Monday night, the school confirmed.

The redshirt freshman completed his first season with the Rebels this fall after transferring to UNLV from Rutgers. He was 20 years old.

"We are devastated to have lost a member of our Rebel family," UNLV coach Barry Odom said in a statement.

"While I had the honor of knowing Ryan for only a couple of months, he already stood out to our coaching staff as an incredible person, student and teammate. Our condolences and prayers go out to Ryan’s family as we grieve along with them over this tremendous loss."

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He appeared in seven games with UNLV this past season, collecting eight tackles and a sack. Keeler earned academic All-Mountain West honors for his outstanding work in the classroom and achieved a 3.8 GPA.

"Words are hard to come by this evening as we grieve the sudden and tragic loss of UNLV student-athlete Ryan Keeler," UNLV President Keith E. Whitfield reflected on Monday. "My sincere condolences are with Ryan's family, friends, loved ones, and teammates during this very difficult time."

The cause of Keeler's death has not been disclosed.

Following Keeler's tragic passing, his former UNLV teammates shared touching tributes on social media.

"Today parents lost a son, teammates lost a teammate, and I lost a friend," tight end Sebastian McQuigg posted on Instagram. "Ryan Keeler was my brother or 'twin' as we would call each other. Ryan was truly someone who put a smile on everyone’s face and was a beacon of joy and laughter."

He added: "Ryan, I’m going to miss all the laughs in the locker room, the Cugino’s runs, and all the future plans we made together. Uncle Ryan and Uncle Sebass, groomsmen at each others' weddings, and more. You’ll be missed forever Ryan, Brother, my Twin. I love you bro."

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Fellow defensive lineman Adam Plant Jr. also shared special words and tweeted several pictures with the caption, "Long Live Ryan Keeler gone way too soon I’m lost for words right now love you forever brother."

Ryan Keeler's family, friends, and the UNLV community are continuing to grieve his huge loss.