Arsenal missed out on the chance to restore their six-point lead at the top of the Premier League table after falling to a 1-1 draw to Brentford on Thursday night.
Manchester City are now four points behind after beating Fulham earlier this week and the Gunners will be worried that their title hopes are about to come crashing down.
After the draw against Brentford, several players were criticised, including Eze who Defoe believes has failed to impress after his move from Crystal Palace.
“I think so, yeah. (it was an uncharacteristic performance) I think it’s the pressure.
“But saying that, it’s a difficult place to go, you know what you’re getting when you go to Brentford. It’s not going to be easy, but you have to try to make it easy.
“You have to cut out individual mistakes, in terms of the concentration levels they have to be high. You have to limit them of chances, they didn’t do that really, I thought Brentford were better in the second half, I thought Arsenal wasted the first half.
“Eze was not good enough. Although I still feel like he’s playing with the handbrake on. I know he hasn’t played games and probably is not match fit, but you still expect a little bit more.
“But they (Arsenal) were different tonight, and I think that’s a mentality thing.”
Eze managed just 17 touches in a disappointing attacking performance under manager Mikel Arteta who has been reluctant to start the England international in recent months as fans begin to wonder why he is struggling so much in North London.