The striker had been expected to return to feature at the weekend versus the Trotters, but Keegan is reluctant to rush Owen's comeback to the first team.
He said in the Evening Chronicle: "Michael probably won't be fit, and Mark Viduka certainly won't be.
"I probably could rush Michael back, and then knock him back five or six weeks.
"And we're probably strong enough to do without the two of them. But when they come back, it'll give us a massive boost.