MANILA, Philippines – Yuka Saso must’ve been itching to launch her LPGA Tour campaign with an all-Callaway equipment after the reigning US Women’s Open champion formalized her tie-up with the leading golf brand in a product test in Hawaii. “I’m so happy to join Callaway and to work with their outstanding Tour team as I start the next phase of my career with their equipment,” said Saso after trying out the new set of clubs during the Sentry Tournament of Champions in Kapalua, Hawaii. The event serves as the launching pad of many big equipment-manufacturer announcements each year, only this time…