Celtic chief executive Peter Lawwell is confident they can improve Gordon Strachan's squad in the summer to meet his ambitions of reaching the Champions League quarterfinals next season.

"We have a plan and understand where Gordon wants to strengthen," said Lawwell. "There are a lot of options. We have developed a track record of doing that. We plan ahead and had a decent January and summer last season.

"We try to keep an edge elsewhere and that's what we have to do as a Scottish club. We operate at our level of the transfer market and that is Scottish club level. We signed Scott Brown for £4m and will continue to do that. However, we are investing heavily in scouting and we are the best in sports science, trying to make our players better. I think you have seen that with Aiden.

"We are not a selling club, either. Aiden has three years left and we are relaxed about the situation. There has been no contact from anyone about Aiden or anyone else."