Roma defender Leandro Castan apologised to coach Luciano Spalletti after their 1-1 draw with Hellas Verona.
Castan's foul gave Giampaolo Pazzini the equalising penalty.
“It was a frustrating day for me in particular," wrote the defender on Twitter.
“I worked so hard to get back to playing football and I thought I was in good shape, but today I realised I have to improve a lot to be there with this team.
“Perhaps people put too much faith in me. I thank them and want to apologise, because I have always tried to do my best with this shirt.
“I am so sorry!!!"