The result leaves second-place Arsenal now 15 points behind leaders Liverpool.
Reacting to the result, Keane was asked if the Gunners could win the Premier League title next season.
"No," he gruffly replied. "Why would I? What makes you think the manager can do it?
"They've got close over the last few years, but City will be strong next year and I'm sure Liverpool will be too.
"Where is the evidence to think they can do it? Getting a striker in would help, have they got the right mentality? Has the manager? You see a different side to them when they're losing every week, but they get all agitated when they're losing.
"I don't think getting a striker in who'll score 20 goals a season will necessarily be the difference.
"Will City and Liverpool just stand still? They're going to look to improve, Pep will bounce back and I think Liverpool will be stronger next season. We don't know where Chelsea are, but what's the evidence or this group of players that they can do it?
"It's alright challenging, but it should be about winning titles.
"Liverpool will be looking at that and not thinking they're going to be put under pressure, they'll be thinking Arsenal have almost given up the title chase.
"There's that striking issue, of course, but I still thought there would be that mentality of getting the job done. If anything, it was the opposite.'
"There would've been frustration from the last few years they didn't get over the line, or get a cup or whatever it might be.
"Then you saw the injuries, and the manager looks frustrated there. The title's gone but he'd still want his club to show a good mentality and try to put pressure on Liverpool. Over the last two or three games, that's gone now.
"They've lost that momentum, what we saw here today was nowhere near good enough. On the one hand, you want to give them credit for the last few years but the next step is the hardest step."