The former winger feels the defender's substitution had a 'big impact' for Queens Park Rangers.
The R's beat Birmingham City during their last Championship outing, breeding confidence that the west London side could finally be kicking into gear under Jimmy Floyd Hasselbaink.
But their inconsistency continued at the weekend as MK Dons beat them by two goals. Next up for QPR is a clash against Derby County and they'll need better at Loftus Road than they produced here.
Sinton was disappointed but also singled out Grant Hall's injury that forced the defender to come off at half-time.
He feels that made a 'big impact' for QPR but also admitted the Dons deserved their victory.
QPR are down to 12th after their loss, while MK Dons remain one place above the relegation zone.
Will the R's get their act together soon or will inconsistency prevail until the end of the season?