Steven Gerrard says Rangers' Covid rule-breakers have been left in "no uncertain terms" about what is expected of them after they were allowed to rejoin his squad.
First-team trio Bongani Zungu, Nathan Patterson and Calvin Bassey, plus academy youngsters Brian Kinnear and Dapo Mebude, were subject of an internal investigation after attending an illegal house party in Glasgow earlier this month.
They have now returned to Rangers' Auchenhowie training base, but only after a strong telling off from their boss.
A statement issued in the name of Gerrard and sporting director Ross Wilson said: "Over the course of the last week, we have both ensured that all our players understand our expectations when you are part of this great club.
"The players involved have been left in no uncertain terms as to the standards that everyone here is expected to adhere to. It has been an extremely difficult week for those players following their admission of an error of judgement whilst dealing with the consequences of their actions.
"Our internal discussions were supported by the immediate honesty shown by the players and an appreciation they fell well below the standards we expect at Rangers Football Club, day in and day out. Those standards form the foundation that we have set as a club in order to achieve our targets as a team.
"The first-team squad players have now returned to Auchenhowie. We are both now satisfied that the players completely understand their obligations to our club and accept with sincerity the strong disciplinary sanctions that we have imposed upon them for letting us all down.
"We accept their apologies to the club, their team-mates and the fans, for whom we are forever grateful for their resolute support and loyalty."
The three senior squad members also issued apologies through the club's TV channel.
Academy graduate Paterson, 19, has missed out on the chance to deputise for injured skipper James Tavernier at right-back.
He told RangersTV: "I just want to take this chance to apologise to my family. I've apologised to the players and assured them nothing like this will ever happen again.
"I've spoken to the gaffer and I've spoken to Ross at great length about the situation and how we move forward.
"I apologise to the fans. Being a Rangers fan since birth and being a player here since the age of eight, I know the privileges and I know the meaning behind the shirt and the high standards that are expected at this top club.
"I've let myself down and I can only ask for the opportunity to go and prove what I can do on the pitch."
Bassey – a summer recruit from Leicester – said: "I'd like to apologise to my family for putting them through this hard time.
"I want to say sorry to the players, to the board, to the manager, to Ross and lastly to the fans.
"I know you are always by our side and have supported us through this journey we've had. I just hope you can carry on supporting us and supporting me.
"I'm sorry for my mistakes and hopefully I can move forward and fulfil my potential at this great club."
And on-loan Amiens midfielder Zungu added: "I'd like to apologise to the Rangers fans. It's been a great season so far for the club and my message is that I'd like to apologise.
"I hope the fans can continue to support us and we can put this behind us and focus on the future."