John Kennedy insists Celtic will fight back from the deep hurt of their trophyless season.
But the Parkhead interim boss admits everyone at the club is now fighting to be part of its future.
Kennedy and his team saw their last chance of winning silverware this term destroyed by Rangers.
Celtic’s 2-0 loss to their rivals at Ibrox means the cabinet is empty for the first time since 2010.
Kennedy admits it’s tough to take, but the pain can act as a motivation and said: “Of course it is (disappointing). That’s what we are all about, trying to win trophies.
“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 than can make you stronger.
“Dealing with that hurt, dealing with the setbacks, make sure you address that properly and move forward.”
Kennedy’s team had a nightmare at both ends of the pitch as they slumped out at the last 16 stage having held the trophy since May 2017.
Celtic lost two preventable first-half goals and missed a host of chances at the other end including a late spot-kick from off-form Odsonne Edouard which was saved by keeper Allan McGregor.
Sweeping changes will now follow the blank term with a new manager set to be appointed at a raft of changes made to the playing personnel.
Kennedy says proving their worth starts now in the final four Premiership games and insisted: “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.”
Kennedy says the winning mentality from the recent past has to be within the future make up and added: “It’s part of Celtic. Whether it’s good, bad or indifferent, you have to have a good mentality.
“They have been a really good squad, I have worked with them for a long time. There have been a lot of challenges this year, it’s been hard to deal with for a lot of players, especially new players coming in, and they have found it difficult to settle as well at times.
“We have had a number of setbacks, but you have to respect that and deal with that and you have to address it going forward. They are a great bunch, I have no issues with them at all.”
