The Spain global stood on Long's calf in the first half of Chelsea's 3-2 win over Southampton at St Mary's in the Premier League at the weekend.
Chelsea wing back Marcos Alonso could miss the FA Cup semifinals after being charged with violent conduct following a challenge on Southampton striker Shane Long in a Premier League game.
Referee Mike Dean failed to produce a yellow card for the challenge which many have seen as a sending-off offence.
"It happened in the 43rd minute of Saturday's game [14/04/18] and was not seen by the match officials but caught on video".
However, the FA has since reviewed footage and sanctioned the Spaniard, who has until 1700 GMT on Wednesday to respond.
Alonso was not penalised for a foul at the time by referee Mike Dean but could receive a retrospective three match ban for violent conduct with a decision expected to be made on Tuesday.
Saints manager Mark Hughes accused Alonso of nearly breaking Long's leg in the challenge, which happened in the 43rd minute of Chelsea's 3-2 victory at St, Mary's Stadium on Saturday.
It would rule him out of Premier League games at Burnley and Swansea, either side of the FA Cup semi-final against Southampton, at Wembley on Sunday.
"It was a poor tackle, and one that could have been more severe for Shane".