Mychel Thompson has joined the Santa Cruz Warriors, Golden State’s NBA Development League affiliate announced Friday afternoon.

Mychel, Klay Thompson’s older brother, went undrafted out of Pepperdine in 2011. A member of the Santa Cruz team that won a D-League title in 2015, he played for Pallacanestro Varese of Italy last season before re-joining the Warriors in February. He averaged 12.6 points, 3.3 rebounds, 1.8 assists and 1.1 steals in 29.1 minutes per game for Santa Cruz.

To clear a spot for Thompson, the Warriors waived guard Amere May, Jr. Santa Cruz opens its 2016-17 season Saturday against the Los Angeles D-Fenders.

Connor Letourneau is a San Francisco Chronicle staff writer. Email: cletourneau@sfchronicle.com. Twitter: @Con_Chron