World number one Rory McIlroy needs to respond to the challenge posed by new US Open champion Jordan Spieth, according to former Ryder Cup captain Paul McGinley.
Spieth's dramatic victory at Chambers Bay on Sunday means he and McIlroy now hold all four major titles between them, the 21-year-old American having won the Masters at Augusta National in April.
McIlroy's lead over Spieth in the world rankings has been cut to 1.72 points - it was 5.30 at the end of 2014 when Spieth was ranked ninth - and the Northern Irishman has lots of points to defend this summer having won the Open Championship, Bridgestone Invitational and US PGA last year.
"Rory has to step up to the plate," McGinley said. "As well as he played to finish fourth in the Masters and ninth here, the bottom line is he left himself too much ground to make up.
"Jordan is putting it to Rory and that can only be good for Rory."
McIlroy was 12 shots behind Spieth after 36 holes at Augusta before closing with rounds of 68 and 66 to cut the deficit in half and finish fourth.
The 26-year-old started Sunday's final round eight off the lead and closed the gap to two after six birdies in 13 holes, but dropped shots on the 15th and 17th to finish in a tie for ninth, five shots off the pace.
However, given his excellent record at St Andrews and his share of third place in the 2010 US PGA at Whistling Straits, the four-time major winner is full of confidence ahead of this year's remaining two majors.
" I feel like I have a great chance in the next two majors," said McIlroy, who shot a record-equalling 63 in the first round of the 2010 Open at St Andrews and has finished second three times in the Dunhill Links Championship, which features two rounds at the Old Course.
"To finish where I did the way I putted this week shows how good my ball striking has been so if I can keep that similar and start to roll in a few putts, I can do even better at St Andrews and Whistling Straits.
" I take a lot of positives out of this. The long game is really in good shape. I've never hit the ball as good in a major championship for four rounds.
"I was really dialled in all week and confident with that. And if I can just get the putting a little bit better and roll a few more in and get a little bit of confidence with that going, I see nothing but positive signs for the next few months."
McIlroy was due to fly home to Belfast on Tuesday and plans to practice at St Andrews before contesting the Scottish Open at Gullane the week before the Open.