Inter Milan's Argentine striker Diego Milito is out for the season after suffering a cruciate ligament injury to his left knee, the club confirmed on Friday.
Milito had only returned to action on Sunday after a month-long spell on the sidelines through injury.
But just seven minutes into the first leg of a Europa League last 32 tie against CFR Cluj he was left writhing in pain, having planted his studs into the turf and twisted and bent his knee as he fell to the ground.
Milito, who has scored nine goals in 20 league appearances this campaign, was later carried off on a stretcher in tears.
A cruciate ligament injury can typically take several months to heal and Inter coach Andrea Stramaccioni said it was a huge blow to the club.
"Yes, unfortunately that takes some of the shine off tonight's win, which was otherwise very positive," he said.
"It's his cruciate ligament, a new type of injury for Diego, nothing to do with the problems he's had before.
"We're gutted for Diego as a person first and foremost, and then of course for what he represents as a player. We need to see when he'll have the operation."
Inter sit fourth, 12 points behind leaders Juventus, and are one of several teams gunning for a top three finish to gain entry to the Champions League.
Stramaccioni added: "Milito is a huge loss for us because he's our only out-and-out centre forward.
"We'd planned for him and (Rodrigo) Palacio to play part of the game each tonight to keep them both fresh, but when you get injured seven minutes into the match it's just sheer bad luck.
"We're all saddened, all of us, and I feel particularly close to the lad personally. We're all very down about it."