If Darmien is a bad example can we take Renato Sanchez? A deal concluded in very quick time, big money signing fee and he will no doubt be representing Portugal at the euros. I don't quite agree with the managing risk view, if that were the case no player would be signed before international tournaments.
Yes, you can say a major injury would affect Zlatan due to age a bit more. But a major injury to sanchez would help drive down his price, and Bayern were happy with the risk.
Zlatan doesn't have much of an injury record either, he keeps himself in great condition. I don't see it as a big risk to announce an agreement before his euro campaign. It would at least give Ed and Mourinho the opportunity to retool the rest of the team with limited time left.
I think, if faced with the opportunity to do so, our club would much prefer announcing the agreement prior to the euros. But if we don't it suggests either we, or zlatan, aren't as interested as the media suggests.