Glasgow Rangers boss Pedro Caixinha has endured a mixed time since arriving at Ibrox earlier in the season.
Brendan Rodgers was appointed the Celtic manager in the summer of 2016.
Ronny Deila spent two years in charge of Celtic before leaving the Scottish Premiership champions last summer.
Former Celtic boss Ronny Deila has claimed that he wanted to sign Moussa Dembele and Scott Sinclair.
Stuart Armstrong is playing well for Celtic this season.
Ronny Deila was in charge of Scottish giants Celtic for two years.
Ibrox outfit Glasgow Rangers recently appointed Pedro Caixinha as their new manager.
The tenacious midfielder is a player reborn under Brendan Rodgers at Celtic.
Manchester City could move for the Norwegian, who is managed by ex-Celtic boss Deila at Valerenga, this summer.
Celtic are one of the most historic sides in European football, so failing to qualify for the Champions League doesn't look good on the CV.