Wawrinka rocked by Queen's blow

It is a major setback for Wawrinka ahead of the July 2 start of Wimbledon, where he has never made it past the quarterfinals.

Wawrinka has struggled to return to peak form since sustaining a left knee injury last year.

Stan Wawrinka's Wimbledon preparations suffered a blow as the Swiss star crashed to a 7-5, 6-7 (3/7), 6-1 defeat against Sam Querrey at Queen's Club on Wednesday.

Wawrinka has struggled to return to peak form since sustaining a left knee injury last year that required two operations and wiped out the second half of the Swiss star's season.

Still hampered by the problem this term, Wawrinka was sidelined again for three months in between a second round exit at the Australian Open and a first round loss in the French Open.

The three-time Grand Slam champion had swatted aside British youngster Cameron Norrie in the first round of the Wimbledon warm-up at Queen's.

But Wawrinka faded badly in the final set against Querrey as the American world number 13 condemned the 33-year-old to his seventh defeat in his last nine ATP Tour matches.

It is a major setback for Wawrinka ahead of the July 2 start of Wimbledon, where he has never made it past the quarterfinals.

Querrey, who won Queen's in 2010, will play Croatian top seed Marin Cilic or Luxembourg's Gilles Muller in the quarterfinals.