"Sharp just runs into him, behind him, so it's a foul," said the Manchester United boss. "[At the other end] no foul. That's two mistakes from the referee."
Lionel Messi marked his return from suspension with a goal in the Copa del Rey on Wednesday as Barcelona survived a scare against Rayo Vallecano to reach the quarter-finals.
Thomas Tuchel admits Chelsea face a fight to finish in the Premier League's top four after his first match ended in a frustrating 0-0 draw against Wolves on Wednesday.