Did Athletics unveil uniform number change in contest?

Pitcher Tommy Milone has worn #57 since joining the Athletics. The team is giving away his signed jersey for a contest today.

However, the jersey features #47. I initially thought that was a mistake. But why would the A’s be giving away a mistake? After all, Milone signed it himself and it would make no sense for an athlete to sign a jersey that isn’t correct.

But on the signature, Milone signed #57 on it.

Maybe Milone changed his number and the Athletics might have accidentally (or maybe intentionally) announced it on Twitter. Or maybe this was a mistake.