The striker was sent off for the first time in his Chelsea career in the FA Cup quarter-final loss at Goodison Park and given an automatic two-match ban, ruling him out of the draw with West Ham and Saturday's Premier League clash with Aston Villa.
Now Costa, who had no case to answer over suggestions he bit Everton midfielder Gareth Barry or made an inappropriate gesture to Everton fans, will also miss the April 9 match at Swansea.
An FA statement read: "Following an independent regulatory commission hearing on Thursday (March 31, 2016), Chelsea's Diego Costa has been given a one-match suspension, fined £20,000 and warned as to his future conduct.
"The forward admitted a charge of improper conduct in relation to his behaviour after he was shown a second yellow card in the FA Cup sixth-round tie on March 12, 2016 at Goodison Park
"This suspension will follow immediately on the conclusion of the player's current ban."
Costa's automatic ban was two games as it was considered to be his second dismissal of the season after he was handed a retrospective three-match ban for altercations with Arsenal's Laurent Koscielny and Gabriel in September
Source : PA
Source: PA