QPR failed to return to winning ways in the Championship, as they were held to a goalless draw at Loftus Road.
Former Rangers winger and current Club Ambassador Sinton was following the game, and he has admitted that Preston defended well.
Over the course of the 90 minutes at Loftus Road, hosts QPR had 57% of the possession, took eight shots of which just one was on target, and earned five corners.
Visitors Preston had 43% of the possession, took six shots of which two were on target, and earned four corners.
Rangers are now 13th in the Championship table with 20 points from 16 matches, eight points behind sixth-place Birmingham City.
QPR will take on Middlesbrough away from home at the Riverside Stadium in the league after the two-week international break.