Arsenal have lost their last two Premier League away matches heading into Monday night's trip to the Riverside Stadium, with defeats against West Brom (3-1) and Crystal Palace (3-0) denting their top-four ambitions.
Wenger's defence was heavily criticised for failing to deal with a physical approach from both West Brom and Palace, and the French coach made a surprise decision to switch to a three-man defence with a 3-4-2-1 formation against Boro.
Hector Bellerin has been dropped after a run of poor performances, while Rob Holding partners Laurent Koscielny and Gabriel in defence - a choice Wenger says he made with a view to giving his side more protection.
"Just to be more solid defensively, we of course have to defend better as a team," he told Sky Sports before the game.
"I felt in the last two games away from home we had a lot of the ball and didn't create a lot and were vulnerable defensively, that's all you hate in the game so let's first try to come back with a good defensive stability.
Asked specifically about his three-man defence, Wenger said: "It's possible yes but we adapt a little bit, we play with three centre-backs yes.
"Recently we lost a lot of direct fights centrally so it will get us a bit stronger in the air."
Wenger revealed that his team is already accustomed to the formation in training, adding: "We already worked before on that in case, we are adaptable because Gabriel can play right-back.
"The system is one thing, we are more focused to have a complete total commitment for every ball and I think that will play a bigger part tonight."