Celtic manager Brendan Rodgers has stressed he wants a "much stronger" squad for next season.
Victory over Rangers on Saturday put the cinch Premiership champions on the verge of retaining their title but by his own admission Rodgers has faced the most challenging season of his career.
It was notable that all 11 players who started against the Gers had arrived at Celtic Park before last summer, when Rodgers returned for his second spell.
The team lost key players such as Giorgios Giakoumakis, Josip Juranovic, Aaron Mooy and Jota in the first half of 2023 and Liel Abada barely featured under Rodgers before also moving on.
Lengthy lay-offs for the likes of Cameron Carter-Vickers and Reo Hatate put further pressure on the depth of Celtic's squad during the campaign.
Of the nine players who arrived last summer, only Luis Palma, Yang Hyun-jun and loan player Paulo Bernardo have hit double figures in terms of starts and Rodgers previously gave strong hints he would have wanted more quality rather than quantity.
Looking ahead to this summer's transfer window, Rodgers said: "We have to (improve the squad). That's pretty clear. But I'm really excited about that moving forward into a real, bright future with this club.
"This season has been a real challenge. The squad is openly not as strong as I would have liked it to have been.
"What the players have given me has been absolutely brilliant but our job going into next year is to be stronger. Much stronger. But that's something that is well under way."
With Joe Hart retiring, a goalkeeper is an obvious priority but Rodgers has also hinted he would like to strengthen the defence while the end of loan deals for Bernardo and Adam Idah will create vacancies in midfield and up front.
Speaking ahead of Wednesday's game at Kilmarnock, Rodgers said: "There's definitely certain positions we would want to have finalised sooner rather than later.
"Ideally, if we can do that it would be great but what's really important for us for this summer is getting the level of quality that I want into the squad. That will be absolutely key for the growth of this team.
"The guys this season have been absolutely fantastic but next season we need more depth in the squad.
"I go back a little bit to my past here - I was going away to Ross County and making eight changes and I was bringing guys like Stuart Armstrong and Ryan Christie into that team. These guys have shown they are Premier League quality.
"I remember taking the team to Dubai at our training camp and the second team beat the starters 5-0, and that gave me great food for thought when we came back for the second part of the season. And it was a proper game of football.
"So that told me the depth that's required and I think that's something that's definitely required here.
"We probably lost a bit of that in the summer and there's no doubt we will need to restructure that. We have some fantastic players here and we want to add to that."
Celtic are in the process of restructuring their transfer approach following the resignation of Mark Lawwell, who was head of first-team scouting and recruitment, and lead first-team scout Joe Dudgeon.
When asked if chief executive Michael Nicholson and others in the club hierarchy are all on the same page as him, Rodgers said: "I have got nothing but support from Michael and the people here.
"But going forward we need to ensure the football structure is very much there and what it is we want to bring in.
"It's not about numbers, it's about increasing the quality of the squad."