Alessandro Florenzi is set to undergo surgery on Thursday after tearing cruciate knee ligaments in Roma's 3-1 win over Sassuolo on Wednesday night.
Florenzi left the pitch on a stretcher in the 85th minute as Roma moved second in Serie A and within two points of leaders Juventus.
"Alessandro Florenzi underwent diagnostic tests during the night which revealed he has ruptured the anterior cruciate ligament in his left knee," read a statement on the Serie A club's website. "The 25-year-old sustained the injury during the second half of Roma's win at Sassuolo on Wednesday evening. Florenzi will undergo surgery on Thursday."
The Italy international is set to miss up to six months, effectively ruling him out until the final few weeks of the season.
"He was squeezing my hand he was in so much pain," Spalletti said after Florenzi was carried off the field at the Mapei Stadium on a stretcher. "We all feel really sorry for him. When something like this happens it takes away all the joy from winning the game. It's not what we needed after a good match."
Get well soon Alessandro #Florenzi. #comebackstronger pic.twitter.com/aw5BMxJAKf
- AS Roma English (@ASRomaEN) October 26, 2016
Before Florenzi's injury, Edin Dzeko's brace had been set to dominate the headlines, as it took him to 10 goals in 10 games this season, the best record in Europe's top leagues and level with Gabriel Batistuta whose feat helped the Giallorossi win the title in 2001.
But Bosnia international Dzeko did not want to get ahead of himself and played down the importance of his form.
"We've just got to take each game as it comes," the 30-year-old said. "If we want to be successful and win games we need everyone pulling in the same direction. I feel good and I'm scoring goals for the team. We won a really tough match today and we're all delighted.
"It was hard today because Sassuolo are a good team with a good coach but we got three goals and we deserved to win."
Batistuta did not score for Roma's next five games after hitting double figures, although he did end the season with 20 goals and the league title. Dzeko found the back of the net only eight times last season and has therefore already improved on that mark.