The Gunners lost 3-1 at the Emirates Stadium against Manchester United last weekend.
"I think we can win there,' Vermaelen told the Daily Mail.
"If we have one of our good days and play as a team we can beat Chelsea. It is important for us to win. There's a gap again - not as big as before - but we have to win to stay in the race."
Vermaelen continued: "All the strikers in England are physical. I think Drogba is the most physical but there is more to him than that. He's one of the best in the world.
"He is so strong that you have to be careful. If you mark him too tight, he grabs you and he's gone.
"You have to adjust to the way he plays. If you are really convinced you can win the header, then you have to go for it.
"But sometimes he uses his body so well that when you jump, he can turn away and you've lost him.
"You have to be smart. Sometimes, let him control the ball and then mark him really tight."
"I'm not that big but when I see some other centre halves they're not much bigger," he added.
"If you have quick players who play quick passes, then you have nothing with your height."