Steven Weber by Mathew Imaging/WireImage.com Steven Weber by Mathew Imaging/WireImage.com

Steven Weber is spending his downtime from wooing Brothers & Sisters' Sarah with a visit to USA Network's Psych. The vet of such series as Wings and Studio 60 will appear in a mid-August episode playing Henry's brother, and thus Shawn's uncle.

Oh, but not just any visiting relative. Weber's Uncle Jack hits town claiming he has a map to hidden Spanish treasure. A race to beat raiders to the loot ensues, with James Roday presumably doing his best Shia LaBeouf.

Weber's casting marks the latest expansion of Shawn's fam - Cybill Shepherd previously was announced as playing the lad's mother, in two episodes starting with the July 18 season opener. - Matt Mitovich