Celtic yesterday rejected a bid for Forster from Southampton which sources at the club described as “significantly short” of the value they place on the England international.
Forster took his place in the Celtic side at Murrayfield last night, keeping one of the easiest clean sheets of his career as KR Reykjavik were swept aside 4-0 in the second leg of the Champions League second qualifying round.
Celtic will face either St Patrick’s Athletic or Legia Warsaw, who play tonight, in the next round and Deila hopes Forster will play a key role in helping the Scottish champions reach the lucrative group phase once again.
“In the end, something will happen with Fraser,” said Deila. “But whether it happens now, in the winter or next summer, I don’t know.
“I want to keep him because I want to qualify for the Champions League and build this team further. We want to keep him here. He has given me no indication he wants to leave. He is an unbelievable professional and I know he wants to play in the Champions League.
“Fraser has done a great job for Celtic but Celtic have also been fantastic for him. I hope that will continue.”
Deila professed himself partially satisfied with Celtic’s performance last night which saw Virgil van Dijk and Teemu Pukki both score doubles to complete a 5-0 aggregate win.
“We started very well and in the first 30 minutes we killed the game by going 3-0 up,” he said. “The tempo was good and we also scored two goals from set plays we had worked on, which was a bonus.
“In the second half, we wanted to do the same things but I don’t think we managed that. That’s something we have to work on in future. We need to play for 90 minutes and really destroy opponents in that situation.”
Deila will travel to Dublin tonight to run the rule over St Patrick’s Athletic and Legia Warsaw who are level at 1-1 after their first leg in Poland last week.
“To play the Irish team would be great for us and it would be a fantastic atmosphere,” he said. “But we will look at both teams closely and know what we have to do.”
Celtic will again play at Murrayfield in the home leg of their next tie and Deila was impressed with his experience at the home of Scottish rugby last night.
“It was fantastic and a great atmosphere,” he said. “I think the next round, it will be even better.”