Stan Wawrinka has turned to former Wimbledon champion Richard Krajicek to further his "knowledge and understanding of the grass".
In 11 appearances at Wimbledon, two-time Grand Slam champion Wawrinka has never reached the semi-finals, losing in the last eight in 2014 and 2015.
Krajicek, now 44, won the men's singles title there in 1996, becoming the first Dutch player to do so.
He will join 31-year-old Wawrinka for the next four weeks.
Wawrinka, who considers clay his best surface, added: "It's a real privilege and honour to add such a champion to my corner."
The Swiss world number five has won both the Australian Open and French Open, also reaching the US Open semi-finals twice.