“But they have been really excellent. You could see how well Stuart did on Sunday to set up Scott Brown’s goal.
“He used his strength, he was very quick and it was a good cut-back.
“It was vital for me that we brought them in early rather than wait until this summer. It is not just about what they do on the pitch, but also how much they have brought off it too.
“They both have a very good attitude, they have settled very quickly and they have also helped with competition every day here.
“They will be big players for us next season, I am sure of that. They have had a taste of European football by playing against Inter Milan in the Europa League and they will have an important part to play as we try to get into the group stage of the Champions League now.”
The Norwegian, who saw the Parkhead side topple out of the final qualifier for the top European prize after losing 1-0 at home to NK Maribor, added: “Our goal now is the group stage.
“If you are a good manager then you learn from the bad things and take with you the positive things and develop.
“I have experienced it. I know how to fail. But I have my thoughts on how we can do it right now.”Deila is considering giving some of his experienced players a break, including skipper Brown, for Friday’s trip to Perth to take on St.Johnstone.
“It has been a great season from everyone and it is the players who deserve the most credit. They have been excellent and since Christmas I think you can see how we got better – we have been really consistent.“We want to keep dominating Scottish football now, but we know that we have to achieve that while also showing that we can live with the best in Europe.
“That is the challenge.”