The 2015-16 Championship season ended only on May 28 when the playoff final took place at the Wembley Stadium in London between Hull City and Sheffield Wednesday.
Rangers’ season finished on May 7, as the London outfit failed to make it to the playoffs.
Pre-season training for Hasselbaink’s side will intensify next season, and former QPR winger Sinclair and ex-City striker Goater are impressed.
QPR endured a disappointing campaign in 2015-16 and failed to finish in the top 10 of the Championship.
Rangers will be aiming to get promoted back to the Premier League at the end of the 2016-17 campaign.
It will not be easy for the London outfit, who will probably have to aim for a playoff spot rather than a top-two finish in the Championship table next season.