Rooney was reacting to Arsenal's 1-0 defeat at Liverpool on Sunday.
Asked on The Wayne Rooney Show if he thought it was now or never for Arsenal, Rooney said: "Maybe not for Arsenal, but I think for Arteta, possibly.
"I think they've allowed him to bring a lot of players in, spend a lot of money. I imagine the board and certainly the fans will be expecting him to win the league. So I think it could be a big year for him.
"(Liverpool) are a very good team. They've got the know-how and the knowledge of winning the league twice over the last few years. It's a sign of a good team when you're winning games."
Rooney added: "If they were just a little bit braver and went and actually took the game a bit more to Liverpool, I think they can go and win that.
"I think that's a real chance missed for Arsenal today. But then I think Liverpool have done what champions do - they stayed in the game."