Celtic's under-pressure manager Ronny Deila was given a vote of confidence by the Scottish champions' chief executive Peter Lawwell on Friday.

Deila endured heavy criticism following Celtic's shock defeat against Maribor in the Champions League play-offs in midweek.

There had already been questions over the former Stromsgodset manager's signings, tactics and team selections since he replaced Neil Lennon during the close season.

And the ill-feeling toward the Norwegian came to a head following the 1-0 defeat by the Slovenians at Parkhead which put them through 2-1 on aggregate and left the Glasgow club in the Europa League.

However, Lawwell is adamant there will be no rush to axe Deila in the Celtic boardroom.

"We can't panic, we've got to keep the head for the longer term," he told Celtic's website.

"You need time in a period of transition and you've got to make allowances for a new manager. Nothing prepares you for the Celtic job.

"We have to do the best thing for the club and its supporters for the longer term.

"He has new ideas, new philosophies and he still has the transfer window in terms of bringing in players. There has been an awful lot to deal with.

"We have every confidence in him and we will back him like we backed all our other managers here, financially and with every support he can get and I am sure he will build a team we will all be proud of."

Lawwell has also come in for stinging criticism for a perceived lack of investment in the club's playing squad.

Celtic have brought in Jason Denayer, Jo Inge Berget, Aleksandar Tonev and Wakaso Mubarak on loan deals as well as goalkeeper Craig Gordon on a free transfer.

But Fraser Forster moved to Southampton for a fee close to £10 million ($13.1m), with Gary Hooper, Victor Wanyama and Kelvin Wilson having also been sold for sizeable fees.

Lawwell tried to play down Celtic's plight when it comes to buying players while maintaining that he will not jeopardise the club's future.

"If you look at (recent Southampton signing) Shane Long, with the greatest respect he was sold for £12m and he scored four goals last year," he said.

"We can't afford that. If you look at Ross McCormack (who joined Fulham for £11 million). We can't afford that or the wages that go along with that."