Chelsea suffered their third Premier League defeat of the season yesterday when they lost 2-1 to bottom-side Crystal Palace at Selhurst Park.
The Blues are now nine points off of Manchester City at the top of the table after just eight games of the season.
Yesterday they were without star striker Alvaro Morata and midfielder N’Golo Kante, who are both nursing injuries.
McManaman says he is shocked at how two players missing affected the side so much against Palace.
I’m absolutely amazed that a couple of injuries in and they look like a ghost side of where they were
“Chelsea are really short up front, really short up front,” the former Liverpool star said of Antonio Conte's side.
“It’s a huge problem for the champions.
“When you’re missing a couple of players, Morata, Kante, you would never think Chelsea, you would never, ever have thought that Chelsea have left themselves short.
“I’m absolutely amazed that a couple of injuries in and they look like a ghost side of where they were last year.
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“They were big and strong and powerful last year, they’re not (now).
“I would say it’s over (the title), I didn’t fancy them to win the league anyway from the end of the transfer window.
“I don’t think anybody chose them (as their favourites).”