Bad news for UFC fans -- Khabib Nurmagomedov will not be competing at UFC 187 and Donald Cerrone now needs a new opponent.

One of the most anticipated matchups in the UFC's lightweight division has been scrapped as Khabib Nurmagomedov has suffered a knee injury in training. This puts UFC 187 at risk of taking its second major hit.

According to MMAJunkie, a source close to the fighter revealed that an injury has forced the undefeated standout to withdraw from a scheduled matchup with Donald Cerrone. The person close to Nurmagomedov spoke on the condition of anonymity as they are not authorized to publicly discuss such matters.

Nurmagomedov, who is set to undergo surgery to repair a torn meniscus in his right knee on Friday, is expected to be out for 4 to 6 months. UFC broke the bad news on Thursday, April 30 evening.

An ACL tear in his right leg has already cost him over a year of competition. In his last bout, he won a decision over Rafael dos Anjos, who is the new lightweight champion after defeating Anthony Pettis in March.

According to FOXSports, Nurmagomedov injured his knee during sparring session in San Jose at the American Kickboxing Academy gym. Nurmagomedov was initially diagnosed with having a torn meniscus, but the fighter sought a second opinion from UFC doctors in Los Angeles, who had the same findings.

Nurmagomedov was slated to fight Donald "Cowboy" Cerrone in a bout that was expected to decide the next 155-pound title challenger on May 23 at UFC 187. He has been replaced by John Makdessi. The Russian mixed martial artist is set to go under the knife once more and hopes to return to the Octagon in October.

This news that comes on the heels of Jon Jones, UFC light heavyweight champion, being suspended, which means that two of the top three scheduled bouts are gone in two days.