Sources: Magomedsharipov out of UFC Boston

One of the most anticipated featherweight fights of the fall is off.

Zabit Magomedsharipov is injured and out of UFC Boston, sources confirmed Friday to ESPN's Ariel Helwani. MMA Junkie was the first to report the news.

Magomedsharipov was scheduled to fight Calvin Kattar in the co-main event of the card Oct. 18. The UFC is seeking a replacement, sources said.

Magomedsharipov (17-1) is 5-0 in the UFC and has not lost a fight since 2013. The Dagestan native is coming off a unanimous decision win over Jeremy Stephens at UFC 235 in March. ESPN ranks the 28-year-old No. 6 among MMA featherweights.

Kattar (20-3) has won two straight by first-round KO/TKO. The Massachusetts native is expected to stay on the card because of his local ties. Kattar, 31, sports a 4-1 UFC record.

UFC Boston is headlined by a light heavyweight fight between former middleweight champion Chris Weidman and rising contender Dominick Reyes.