The England striker has not kicked a ball in any of Newcastle's five friendlies, and the reasons for his omission seem to change daily.
As well as having mumps, his reason for missing the first two games, he allegedly suffered with a calf problem.
Keegan Plays Down Owen Concern!
Keegan has now revealed he is also unlikely to feature in the final friendly of the summer against Valencia.
Keegan: "I don't think he will play against Valencia.
"Michael will want to play and maybe have half a match, but I've told him I won't risk him.
"He'll be fit for Manchester United as long as he doesn't have any setbacks.
"He's just started running again and done a lot of strength work. He's a very fit boy.
"We must get some football into him again now but we can do that internally without throwing him into a game five days after his comeback."