The ex-center half has likened Odegaard’s impact at the Gunners to that of Cole Palmer at Chelsea.
Odegaard finally returned in the 1-1 draw against Chelsea before the international break, having been out for weeks with an ankle injury before then.
Speaking with talkSPORT, Keown said: "I think that does become obvious when Odegaard is not available.
"It was very significant the creativity that he created, it'll be like taking Cole Palmer out of the Chelsea team when you consider how well Odegaard did.
"I think first of all, to come back from being out for six weeks and to hit the ground running like he did shows you how he's applied himself when he's been out.
"He set up Arsenal's goal, it was great to see Martinelli put that one away, but more recently, we've become predictable around the opponents goal.
"And maybe that's top of the shopping list for a striker to come in, but really, the problem for Arsenal so far this season has been about discipline and injuries."
He added: "Now that Odegaard is back, I think the way that he performed (against Chelsea) deserves praise.
"To be out that long shows you how hard-working he is, he hit the ground running, he created the goal.
"Arteta will be praying and hoping that the luck now turns around."
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