Richards out for around 10 days
Micah Richards will miss Fiorentina's UEFA Europa League semi-final second leg against Sevilla with a hamstring injury.
The England international joined Fiorentina on a season-long loan from Manchester City, and has made 19 appearances in all competitions.
Richards came on as a substitute during the 3-0 defeat to Sevilla in the first leg last week, but will play no part in the return on Thursday.
"Micah Richards underwent tests today which confirmed that he has suffered a minor strain to his left hamstring," a Fiorentina statement read.
"The English defender will be out for around 10 days while he recovers.
"Manuel Vargas also underwent tests today which revealed a strain to his right adductor muscle. Vargas will embark on a two-week treatment programme, at the end of which the Peruvian will have further tests."