Harlequins director of rugby Conor O’Shea has delivered a frightening warning to his side’s Premiership title rivals – Quins are way short of their potential.

The champions, shorn of their international contingent, crashed to a 31-15 defeat at Castres last Thursday as they prepared for the defence of the crown they claimed in May.

Quins kick off their campaign with the London double header on September 1 when they take on Wasps at Twickenham.

And while last week’s defeat was not the ideal start, O’Shea insisted his men are determined to be a better side than the one that beat Leicester Tigers in the Premiership final.

“We are nowhere near where we can be,” said O’Shea this week.

“We want to be the best in everything we do and that goes for stats like tries conceded, tries scored, penalties conceded and yards made. There is plenty of room for impovement yet.”

Quins host Connacht and London Scottish in a friendly double header at the Stoop on Saturday, in a move designed to give all players meaningful game time.

“Rather than give players 40 minutes here and there this is an opportunity to pick two different teams and get them playing a whole match together,” added O’Shea.

“Some will play one game and bench for another, so it will be a tough test.”

“The game in France was all about  getting a good first hit out, more than the result and there was a lot we learned.

“There are some senior players itching to get on with things and show what they can do.”