Hurting John Kennedy admits Celtic's stars are now playing for their Parkhead futures.
The club have been consigned to a first trophyless season since 2009 after being dumped out of the Scottish Cup by Premiership champions Rangers.
Kennedy hinted there will be major upheaval when an as-yet unappointed new manager takes the reins.
With just four games of a now meaningless league campaign to go, the interim boss doesn't want to see players feeling sorry for themselves.
Conversely, he's looking for a reaction Celtic can take into next season.
“Of course it is (disappointing). That’s what we are all about, trying to win trophies," Kennedy said.
“We have been dominant in recent years and, when you don’t, it hurts.
“When you hit a setback and things aren’t quite falling for you it all seems to come at the one time and that’s been the case.
“We have to take what we can out of the season, it’s not been a very successful one, but sometimes that can make you stronger.
“Dealing with that hurt, dealing with the setbacks, make sure you address that properly and move forward.
“There is nothing to play for in terms of trophies, but you have to bring mentality. That’s what you have to show at this club.
“As soon as you pull on the shirt and step on the pitch you are representing the team, the club and the fanbase.
“We can’t stop and feel sorry for ourselves. We have to keep working and put performances in and that can lead into next season.
“We know the mentality of the players and we know there might be gaps in the summer. There will be players coming in and out and they have a terrific attitude.
“I don’t have an issue in terms of how they approach training and when we are doing things, but you are always playing for your future.
“If there is going to be change, people might see things differently and people might have to show themselves again.
“And, if there is a change, some styles might fit one player and not another and we will have to address things.
“I can’t put a number on it, but, in terms of the squad, we need to add to that.
“We have lost a couple of players, a couple might be coming out of contract, these decisions will be made in the summer.
“I don’t want to overly talk about it. We are losing our captain Scott Brown, so there will certainly be changes, maybe a little more than we normally do.”
