Leeds Carnegie Director of Rugby Stuart Lancaster was reflected his disappointment after seeing his side go down 39-15 to Quins on Saturday evening.
Leeds were their own worst enemy with unforced errors gifting the home side possession which they exploited.
Speaking after the game, Lancaster commented, "We were disappointed with the performance today and the players will be frustrated when they review the game. There are positives to take out of the game but our mistakes put us under too much pressure and credit to Quins who took their chances.
"I thought our performance improved in the second half, especially at the set piece, and when we retained possession we did challenge them. What we have to do now is focus on the positives, learn from our mistakes and direct our energies into next weeks match against Saracens," added Lancaster.
Having lost Alberto Di Bernardo and Hendre Fourie in the first half of last weeks game, Leeds were dealt another blow this week when last season's Player of the Year Jon Dunbar limped out of the game after a minute with a torn hamstring. The back row had planted his leg only to have a team mate come over the top of his back and force his head down towards his knee, forcing the hamstring to give way.
Lancaster commented, "It was obviously disappointing to lose Jon Dunbar in the first minute of the game and the depth of our squad would be tested in the forthcoming weeks. However, all the players have a great self belief and belief in each other. I will be reinforcing that through the week and we will be working hard to improve in all areas. "We are looking forward to welcoming back Mike MacDonald and Fosi Pala'amo from the World Cup and seeing Rob Vickerman make his comeback on Monday night in the A team at Rotherham," added Lancaster.