Celtic boss Brendan Rodgers has admitted that his side need to bring in new recruits ahead of the new campaign.
The club have already signed Odsonne Edouard following his loan spell in Glasgow last season, while Lewis Morgan has also joined from St Mirren.
Celtic have lost both Stuart Armstrong and Patrick Roberts to Southampton and Manchester City, however, and according to Rodgers, the team needs new additions.
"There is no doubt we need to replace, never mind add," the manager told Radio Clyde.
"We have lost the likes of Stuart Armstrong, who was a very important player for our squad, and the likes of Patrick Roberts, who was very important for us.
"We need to replace those players and that's something we hope the club can do over the course of the summer."
Left-back Kieran Tierney has also been linked with a move away from Scotland, with Everton allegedly interested in the defender.