Mickelson has been unable to find his best form in previous contests

Phil Mickelson insists he is carrying no negative thoughts into the Ryder Cup despite being on the losing side on five out of six occasions.

The world number two, 38, has a losing record in the bi-annual contest, with nine wins, 12 defeats and four halves.

"I don't know why we haven't been able to play at the same level in the Ryder Cup as we have in the Presidents Cup.

"But I don't feel as though there are any scars, given that we've had success in the alternate years," he said.

The San Diego-born left-hander, who has won two PGA Tour titles this year, denied that three straight defeats at the hands of the Europeans had left the US team carrying mental baggage into this year's event.

I think the leadership has really come from our captain Phil Mickelson

"But I feel like The Presidents Cup has given us team competitions, team experiences that we've done very well in and succeeded in.

"And the key for us will be doing it in a Ryder Cup."

With world number one Tiger Woods absent through injury, Mickelson will assume the burden of providing a lead for his team-mates, but he was reluctant to accept he has a clear leadership role.

"My only responsibility is to play well," he added. "That's something I've been working on, and all of the players have been working hard on this last week.

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"I think he's been a great captain and has given us great direction.

"One of the biggest challenges heading into a Ryder Cup is some of the uncertainty we'll face during the week.

"He's done a great job of letting everybody know what to expect. I feel like the guys who have not played in this event are ready to play, so I think the leadership has really come from our captain."