Concerned Ally McCoist believes Neil Lennon is in the midst of his biggest battle of his long-running Celtic tenure.
The defiant Hoops boss insisted in the wake of Thursday's 4-1 Europa League thumping to Sparta Prague that he is the right man to turn things around.
McCoist admits he also has doubts over the 49-year-old's claim that Celtic 's abysmal run of two wins in nine isn't his ultimate fight of his Parkhead managerial career that has spanned two tenures and 11 years.
But the Rangers hero believes Lennon has the fighting spirit to bounce back with his team plunging into free fall on the pitch.
Speaking on BT Sport, McCoist said: "Listen, that's the kind of character he is.
"He's never shirked an issue, on and off the pitch, in his life and he's not going to do it now.
"Where I would disagree with him, I'm not sure I can remember many more testing times for Neil Lennon or Celtic looking at the way they are at this moment in time.
"I keep saying, I have said for a while, that they will improve, they have to improve."
The defeat means Celtic can turn their focus to domestic matters as they aim to bridge the current 11-point gap between themselves and Rangers at the top of the Premiership.
And McCoist has called upon the players to make a difference and help their manager out following their latest disastrous result.
He added: "I would have probably picked that same side.
"That's still a strong Celtic side that will go out and do the business but it didn't.
"The buck will always stop with the manager and the head coach, that's the way it has been for a number of years, that won't change.
"But the players have got to have a look at themselves, especially defensively."
