In the wake of Sunday’s Scottish Cup semi-final defeat at Hampden, the Celtic board of directors are now expected to call time on Deila’s tenure this summer.
It is understood the Norwegian will remain in charge for the remainder of the Premiership title run-in, with Celtic enjoying an eight-point lead over nearest challengers Aberdeen at the top of the table with just five games left to play.
Warburton has been taken aback by the level of condemnation Deila has been subjected to in a campaign which sees him still on course to win his second successive Premiership crown. The Englishman feels Deila should not be in a position where his future is uncertain, regardless of whether or not he leads Celtic to the title.
“Is winning the league not enough?,” said Warburton. “If it’s not, then tell him. All managers in all divisions have to ask ‘what represents success?’
If you tell them the answer, then they know where they stand. Have it in black and white at the start of the season.
“I don’t want to comment about another club and its manager, but all I know is that I’ve met Ronny and he came across as a real gentleman.
“He comes across as someone who has received a lot of unfair abuse and someone who wasn’t deserving of a lot of the criticism that came his way. I passed him in the corridor on Sunday after the game and thought he didn’t deserve what was coming.
“He can turn around quite rightly and say he was just inches away from winning that game.
“That’s the nature of the game we’re involved in.
“Unfortunately, I didn’t get a chance to get a drink and chat with him afterwards, which was a shame. It doesn’t work that way at Hampden but, if the game had been at Ibrox or Parkhead, I absolutely would have.
“We just shook hands after the penalties. But we had spoken at the pre-match press conference on Friday and he just came across as a very humble, very pleasant guy. I enjoyed speaking to him.
“On Sunday, walking down that corridor at Hampden after the game, I just didn’t think someone of that nature deserved to be put in that position.”