[Spence]

Originally Posted by RKBUmp

SECTION 3
All fielders must wear gloves or mitts made of leather or other approved materials. Only the catcher and first baseman may wear mitts. The glove worn by a pitcher must be uniform in color. Gloves or mitts optic yellow circles on the outside, giving the appearance of a ball, may not be worn by any player and will be considered illegal.

I would say the bolded section does state no other player than the catcher and 1st base can wear a mitt.

Thanks. Looks like it was the correct ruling.