Wenger reasons that this is because of the way the modern game is played, where the two centre-backs have to build the play from the back.
"[The role] is changing to increase the shape of the teams," he told Arsenal's official website. "The traditional shape of football was 4-4-2 and the new shape is to have one isolated striker.
"In a 4-4-2 system, the two full-backs get the ball first because the two strikers are in the middle and the two centre-backs are marked so the keeper's first solution is to the full-backs.
"In the modern game, the two full-backs are marked by two wingers or wide midfielders and the first available player are the centre-backs as they are playing two against one."
Wenger then underlined how this affects the two central defenders.
"That means the importance of that technical quality is much more important," said the 62-year-old.
"Even if they are less good defensively, they have less to deal with than two against two - they are always in a two against one situation.
"The start of the game is with the centre-backs nowadays, and that's why that technical ability has suddenly become important."
Arsenal are at West Ham United in the Premier League on Saturday.