Vermaelen had lost his place in the Arsenal starting line-up with the partnership of Per Mertesacker and Laurent Koscielny keeping him on the sidelines. The Catalan club moved to add him to their growing defensive contingent, beating Manchester United to the punch.
But that is now looking like the best £15 million that Manchester United didn't spend.
His injury record at Arsenal was not great anyway, but when signed by Barca he had a niggling problem with his thigh picked up in the World Cup with Belgium.
That thigh problem has now become far worse than first feared. It has prevented Vermaelen from playing a competitive game for his new club yet and he is now out for five months. He had surgery on his thigh problem yesterday, which will leave him out of action well into 2015. When he finally plays his first game for Barca it should be at least nine months since they signed him.
Manchester United are certainly better off with the likes of Marcos Rojo, Tyler Blackett and Paddy McNair then Vermaelen - who is starting to become something of a permanent crock.