Mickelson has only ever won one major - the 2004 Masters

The 35-year-old, who came third in last year's Open, believes he has adapted to the challenge of links courses.

"I do feel more confident than in years past because of the finish I had last year," said the 2004 Masters champion.

"I've enjoyed the different style of golf in the last few (Opens), and I'm starting to play better."

Mickelson fired a closing 68 at Royal Troon a year ago to finish just one shot outside a play-off for the title.

"I'm feeling very comfortable now with the bump-and-run shots required for links course golf and I'm looking forward to hitting each one," he added.

Todd Hamilton beat Ernie Els in the play-off to claim a surprise victory, but Mickelson's third place was his best result in 12 Open starts.

Five holes at the Old Course have been lengthened, adding 164 yards to the card.

"There's an advantage to hitting the ball long but the winner is going to have a lot of creativity into the greens," said Mickelson, the world number four.

"The winner is going to be hitting bump-and-run shots that have a lot of touch and using the slopes properly, as opposed to someone who just bombs it.

"The course is playing the way it was supposed to play years ago. I can't wait to get back there."

On Thursday, Mickelson is scheduled to tee off at the Scottish Open in Loch Lomond with defending champion Thomas Levet of France and world number five Retief Goosen of South Africa. The trio start at 0800 BST.

Scotland's Colin Montgomerie leads the home challenge.