UEFA has rejected Rangers' appeal against Kemar Roofe's four-game ban for "dangerously assaulting" Slavia Prague goalkeeper Ondrej Kolar.
Roofe was sent off during Rangers' controversial Europa League last-16 second-leg defeat to the Czech side in March, after his boot made contact with Kolar's face when he challenged for the ball.
Rangers lost the second leg 2-0 and were eliminated 3-1 on aggregate.
The Czech keeper was left with a fractured skull, but Rangers appealed against Roofe's ban, claiming the punishment was "severe".
However, in a statement on Monday UEFA said: "The appeal lodged by Rangers FC has been dismissed.
"Consequently the UEFA control, ethics and disciplinary body's (CEDB) decision of 13 April 2021 is confirmed.
"The CEDB had decided to suspend Rangers FC player, Mr Kemar Roofe, for four UEFA club competition matches for which he would be otherwise eligible, for dangerously assaulting another player."
The former Leeds and Anderlecht forward will now have to sit out when Steven Gerrard's team kick off their bid to qualify for the Champions League.
Rangers are scheduled to begin their quest to return to the group stages of the competition for the first time in a decade on August 3 when they enter the third qualifying round.
Roofe's challenge on Kolar was the first flashpoint on a very controversial night at Ibrox.
Glen Kamara and his team-mates reacted with fury after the Gers midfielder was allegedly racially abused by Slavia defender Ondrej Kudela.
Kudela was hit with a 10-game suspension - ruling him out of this summer's European Championship if his appeal against the ban is not successful - while Kamara was also punished with a three-match ban for allegedly assaulting Kudela in the Ibrox tunnel after the game.
Rangers have also appealed against that ban, but UEFA have yet to announce their decision.