I doubt he'll want to stay regardless of where they finish.
He's been there since 20 yo, and just wants a new challenge I guess. He's done it all at United.
Maybe wants a new area, new club, new stadium, a new lease of life. He's 28, so in his prime.
His game isn't built of physicality or being athletic, it's built of hard-work, accuracy and just generally being a MAD Man who wants to win at all costs.
These things don't deteriorate and it comes from the heart, rather than the legs. He could go on to be class at 32/33... So a good 4 years in him.