Rodgers is currently on the look out for a new forward to fill the void left by talisman Luis Suarez, who earlier this month sealed a £75m switch to Barcelona.
The Reds were close to sealing a £8.5m deal for QPR forward Loic Remy, but pulled the plug on the transfer and are yet to comment on the specific reason why the move has been scrapped.
It is believed Remy failed his medical and Rodgers has admitted that he is willing to wait until January to sign a frontman.
But Nicol, who spent 13 years at Anfield, says Rodgers cannot afford to wait and will put Liverpool's chances of remaining in the top four in serious jeopardy if he does not sign a new forward to support Daniel Sturridge in attack.
"If they don't sign another centre-forward they'll struggle to get back into the top four," Nicol told talkSPORT.
"There doesn't seem to be anybody available who has Loic Remy's track record. It's bad news for Liverpool more than anyone else.
"Remy is going to go back to QPR and he's going to score goals. Harry Redknapp is the one who is going to benefit.
"You can't expect Daniel Sturridge to do it all on his own.
"He's shown he can play up front, score goals and carry the team for a certain amount of time.
"Without another striker though, in case he gets injured, they are up the creek without a paddle.
"There isn't another striker currently at the club that is going to take them into the top four, never mind challenge for the Premier League title.
"Liverpool are in trouble. They have to find somebody and I'm not sure where they're going to find them."
