Eddie Howe is being linked with Crystal Palace and Newcastle United.
The Sunday World says Celtic have turned their attention away from Howe after the Englishman could not bring the backroom team he wanted to Parkhead.
The former Bournemouth boss was the front-runner to replace Neil Lennon, who resigned in February with Old Firm rivals Rangers well on their way to stopping the Hoops' quest for a 10th successive Premiership title.
It was widely believed that the hold-up in Howe's appointment was due to Bournemouth being involved in the Championship play-offs, with Howe reportedly looking to bring first-team coaches Stephen Purches and Simon Weatherstone as well as the Cherries' technical director Richard Hughes to Glasgow.
It is understood Celtic were willing to accommodate Howe's requests but that the former Burnley boss will not move north of the border because he is unable to assemble the backroom staff he wanted.
Howe has also been strongly linked with a move to replace Steve Bruce as Newcastle manager, while he has also been mentioned as a contender to take over at Crystal Palace.