Fabregas scored twice from the bench in the 3-0 defeat of Aston Villa on Sunday to reaffirm his position as Arsene Wenger's key man, with the Spain international now topping Arsenal's charts in both goals and assists.
And Belgian defender Vermaelen has become just the latest player to heap praise on the Catalan midfielder.
"He is the best midfielder I have played alongside,'' Vermaelen told his club's website. "He's really smart in his game and in training if you play against him he's really difficult to defend against because I think he has eyes in the back of his head. He sees everything.
"He is a good captain too. He has a lot of qualities in football and I think that's important for a captain. He talks in the dressing room, not too much but just enough.
"For us he was very important on Sunday. He scored twice in 20 minutes so he was very important. I think before he came on we were the better team but we didn't create too many chances, and when he came on we controlled the game more and we created some more chances.
"He played some good passes behind the defence, they were really dangerous. He has a great vision in the game.''
However, Fabregas could be out for three weeks after he suffered a recurrence of a recent hamstring injury against Villa. Summer recruit Vermaelen, though, has backed his team-mates to fill the gap left by Fabregas' absence.
Ahead of Wednesday's clash with Portsmouth, he said: "Cesc is very important for us - it's the same with Robin van Persie, who is also important for us - but they're injured and we have to do it without them. I think we have other good midfielders who can fill that gap.''