Nicolas Gonzalez's penalty and a strike from Giacomo Bonaventura condemned Roma to a second defeat in its past three league games – as many as Mourinho's team had suffered in its previous 17 – as Fiorentina drew level with the Giallorossi in the race for a European spot.

Although Roma sealed a place in the Europa Conference League final by beating Leicester City last Thursday, its hopes of a top-six league finish are under threat after going four league games without a win for the first time under Mourinho.

However, while the former Chelsea boss admitted his side had been second best after a draining few days, he was angered by the decision to award Fiorentina its early spot-kick.

Mourinho used his post-match interview to lay into VAR Luca Banti, recounting a series of officiating decisions he believes to have gone against Roma.

"Today there is a double explanation for the defeat. One is that after Thursday's match we had less physical and mental energy, and we knew it, against a team that had been preparing all week," he said.

"Then another explanation I wanted to hear from Banti of Livorno, which is not a city far from here. There is a touch, it is not a foul. Banti intervenes. Let's talk about today's three points and let's finish like this. Beyond Banti, Fiorentina was stronger and deserved [to win].

"But the problem is that we are not just talking about today, we are talking about Venice, Bologna, many episodes that have no explanation. 

"Where is Banti now? Why did he call [referee Marco] Guida, who was ten metres away and saw that it wasn't a penalty? This is the explanation I would like but do not have. 

"We have a Conference League final, which absorbs emotions and energies. It is not easy in Rome to forget. But we have a championship to play and what happened to this team is really too much.

"I would like the respect of those like Banti, who, sitting in their chairs, have taken away many points."

Gonzalez's fifth-minute spot-kick represented the first time Roma have conceded from a penalty in the first five minutes of a league match since May 2006, when Milan legend Kaka converted against them after four minutes 30 seconds.

Meanwhile, Mourinho said the physical toll of his team's European campaign had left it at a disadvantage on its trip to Florence.

"The difference lies in the fourteen more games played [compared to] Fiorentina, who played one game a week throughout the season," he added.

"Count fourteen games with more than 10 kilometres per game [per player], and there are many. The difference is all here."

Roma is sixth in Serie A, three points behind fifth-placed Lazio and ahead of both Fiorentina and Atalanta by virtue of their head-to-head records with just two games remaining.

Mourinho was at least afforded one bit of positive news in Florence, as he was able to hand Italy full-back Leonardo Spinazzola a four-minute cameo from the bench.

That marked Spinazzola's first Serie A appearance for 379 days, having last featured against Cagliari on 25 April last year, prior to suffering an Achilles tendon injury when representing his country at Euro 2020.