Newcastle have failed in an appeal to have the red card defender Fabian Schar received during Sunday's Premier League defeat by Arsenal overturned.
The Switzerland international was dismissed by referee Mike Dean for a challenge on Gabriel Martinelli after coming on as a substitute late in the Gunners' 2-0 win at St James' Park, his first appearance since recovering from a knee injury suffered in February.
He will now miss Friday night's trip to Leicester and the home games against Manchester City and Sheffield United.
A statement on the club's official website said: "Newcastle United's appeal against Fabian Schar's red card, picked up during Sunday's match against Arsenal, has been unsuccessful.
"Schar was dismissed by referee Mike Dean in the 90th minute of the game following a tackle on Gabriel Martinelli.
"An independent panel reviewed the incident following United's appeal to the Football Association but has upheld the decision.
"The Swiss defender will miss United's next three matches against Leicester City, Manchester City and Sheffield United."