( CNN ) -- U.S. Open champion Webb Simpson pulled out this year 's British Open Friday because his wife is due to give birth later this month . Simpson was set to fly in next week to the third major of the season at Royal Lytham and St Annes from July 19-22 but has decided against making the trip . A statement issued by tournament organizers said : `` Webb Simpson , the 2012 U.S. Open Champion , has withdrawn from The Open Championship due to family reasons . '' A number of leading contenders have been tuning up for Lytham at this week 's Scottish Open and there was a welcome return to form for four-time major champion Phil Mickelson . Mickelson holed his second shot for an eagle two at his opening hole at Castle Stuart and backed it up with six birdies for a second round eight-under 64 . The American had opened with a disappointing 73 at the links course in Inverness but on seven-under 137 at halfway is handily placed for a weekend charge . `` There was big difference today compared to my 73 yesterday as I just hit a lot better shots , struck it solidly and made a few more putts , '' he told he official European Tour website . `` I have only played three tournaments the last couple of months so I knew I just needed to play more , and I 'm glad I added this tournament . '' Mickelson finished joint runner-up to Darren Clarke at last year 's British Open and his last victory came at February 's AT & T Pebble Beach National Pro-Am where he finished with a 64 . He trails joint leaders Alexander Noren of Sweden and Italian Francesco Molinari by five shots . Molinari had led after the opening round with a superb 62 but came back to the field with second round 70 . Defending champion and world number one Luke Donald stayed in contention on nine-under after a 68 , seeking his second win in his last three starts on the European Tour .
U.S. Open champion Webb Simpson out of British Open . The Associated Press contributed to this report. Phil Mickelson shoots eight-under-par 64 at Scottish Open . Alexander Noren and Francesco Molinari joint leaders at Castle Stuart .