Frank Lampard has been charged with misconduct by the Football Association (FA) after Derby County's Championship game against Birmingham City.
Lampard confronted referee Simon Hooper after a 2-2 draw last Friday, the Derby boss feeling his side had been denied a penalty.
"The players gave everything and if we'd got the clear penalty on Craig Bryson, it would have won a very tight game," Lampard told reporters.
Lampard has until 18:00 BST on Monday to respond to an FA charge that alleges "his language and/or behaviour on the field of play after the conclusion of the fixture amounts to improper conduct".
It is the second time this season Lampard, in his first campaign as a manager, has been in trouble with the FA.
In September the former Chelsea and England midfielder accepted a fine of £2,000 after he was sent off during a defeat to Rotherham United.
Derby are on track to qualify for the play-offs, with Lampard's side sixth in the table and with a game in hand over seventh-placed Middlesbrough.