There was no immediate comment from AS Roma on the future of coach Eusebio Di Francesco, who was already under pressure after a 3-0 derby defeat to Lazio on Saturday.
Di Francesco's position at Roma has been under the scanner for several months due to their lacklustre league form this season, where they are fifth in the Serie A standings.
"On behalf of myself and everyone at AS Roma, I'd like to thank Eusebio for his work and his commitment", team president Jim Pallotta said in a release.
Di Francesco, 49, took over in June 2017, leading Roma to last year's Champions League semi-finals, where they were beaten by Liverpool.
Domestically, Roma now sit fifth in the Serie A table, three points behind Inter for the final Champions League place.
The veteran Italian boss - who won the Premier League title with Leicester in 2016 - was sacked by Fulham last week, with the club appearing destined for the drop.
Monchi apologised after he was involved in an incident with Roma fans at the airport as the team returned home from Portugal on Thursday, though he said it was not as bad as reported in the Italian media.
Roma had several chances to level and also had a penalty appeal of their own turned down late in extra time, when the video review showed Marega had not fouled Patrik Schick.
Francesco's sacking comes just a day after the Serie A giants were bundled out of the Champions League in the round of 16.