Injured Leg?

Hi there.

We’ve had one budgie (Booster) for 3 years now, decided to get a second one (Blue) and this happened when we brought him home:

As we were taking him out of the box he was in to put into the cage he slipped out of my hands and flew off, he's only 5 weeks old so cant fly well, anyway he ended up stuck behind a radiator. Managed to get him out quite quickly and get him into the cage but i noticed his foot looked a bit odd, in the picture its the one on the right. He doesn't seem to be able to uncurl it, and when he stands on it it stays tucked under him. 

So my question is, does it look like its been injured? Is this something that might sort itself out/heal over time or should i take him to a vet?

Thanks in advance.