Rangers legend Barry Ferguson insists Celtic are playing "catch-up" to Rangers before a ball is kicked in the title race.
The Scottish league season begins again on Saturday as Ange Postecoglou's Hoops aim to take back the Premiership title from Steven Gerrard's side.
A summer recruitment drive has seen Carl Starfelt and Kyogo Furuhashi sign for Celtic in recent weeks but both remain in self-isolation and won't play in Wednesday night's all-important Champions League qualifier at Midtjylland while youngsters Liel Abada, Liam Shaw and Osaze Urhoghide are in the door.
They remain light in defence and Ferguson believes a monumental effort is needed to match the Gers squad in the coming weeks.
The champions have added John Lundstram, Fashion Sakala and Nnamdi Ofoborh all on free transfers, though the latter player is taking time out of the game for now after a heart problem was discovered in a scan.
The Alloa manager told the Go Radio Football Show: "Rangers are the clear favourites, no doubt in my mind.
"The business they have done, they have done really early as they have done the previous season.
"It looks as if Celtic are once again playing catch up. For me, I think Rangers are, if they concentrate on themselves and get off to a good start, they will be difficult to peg back.
"They (Celtic) need to sign players. It's difficult to get good players with the time that Ange came on. It was pretty late on.
"Quite a lot of business already done and people have agreed deals. They have not signed with clubs but virtually agreed with them.
"He is clearly frustrated and he has brought a few players in but he's wanting another four or five, but it's hard to do.
"Money, as well, have Celtic got the money to spend? They have brought £13.5million in for Ajer, which I think is brilliant business going into the final year of his contract, but Celtic are playing catch up.
"Rangers are clear favourites at this moment in time."
