Mowbray will check in at Parkhead on Wednesday morning to meet the media after signing a 12-month rolling contract on Tuesday.
The former West Brom boss will be joined in the east end of Glasgow by Mark Venus, his assistant at The Hawthorns, and Peter Grant, his first-team coach at Albion and a former Celtic team-mate.
Current Parkhead coach Neil Lennon will join the new management team but his role is as yet unknown but what is known is that Mowbray will be immediately under pressure to wrest the Scottish Premier League title back from Old Firm rivals Rangers.
Nicholas, who had two spells as a striker at the Parkhead club, insists Mowbray has to find at least one player who can excite the Celtic fans.
"I am very happy with Tony becoming manager, he is the right guy to improve the team," he told Sky Sports.
"I just hope that he gets a relatively decent budget because the current Celtic team needs fresh faces.
"I think it probably needs a couple of star names.
"I'm not talking about £50,000 per week (wages) or spending £10million (on fees) but we need to find someone to get the Celtic fans back onside, someone they can sing about and someone who can become a hero.
"They haven't had one for a little while."
Nicholas is looking forward to an improvement in Celtic's style of play but warned Mowbray results must follow.
He said: "There will be a few Celtic fans who are not convinced by Tony Mowbray because West Brom were relegated last year.
"But the secret to this appointment is that Tony will play the Celtic way.
"A lot of Celtic fans have said that the team didn't play that way under Gordon Strachan even though he was successful.
"He won three titles back-to-back and people were still criticising him.
"But just playing the right way, saying the right things and having the right mentality doesn't always get you the prizes.
"The late and great Tommy Burns lost one league game (as Celtic manager) and Rangers still won the league.
"It was one of the best Celtic teams for a long, long time and Tommy had to bear the burden for that.
"There will be the same scrutiny for Tony, that's what happens at Celtic and Rangers."