The Arsenal skipper's drawn out transfer saga appears to be coming to a close with a deal finally expected to be completed this weekend, according to several sources.
Fabregas has scored 57 goals in more than 300 appearances for Arsenal since joining from Barcelona in 2003, but Robson is not convinced of the Spaniard's leadership qualities.
"You can't call [Cesc Fabregas] a leader," Robson told talkSPORT.
"Thierry Henry wasn't a leader. He was, in my view, a poor captain. When things were going wrong for Arsenal he never stepped up.
"And when things were going wrong for Arsenal, Cesc Fabregas didn't always step up either. There was that game at Newcastle last year where Cesc Fabregas was brilliant in the first-half and you didn't see him in the second-half.
"That's where Cesc Fabregas won't be a loss as a leader because the feeling I get is that he'd lost interest in the club for a whole year and he wasn't a good influence on some of the other players."
Fabregas will reportedly join the European champions in a deal worth 30million euros (£27million), with an additional 6million euros (£5.2million) in performance-based add-ons at a later stage.
There are also suggestions Fabregas is prepared to wave the £4million compensation he would be entitled to for the remainder of his long-term Arsenal contract, as technically the player never asked for a transfer.