Tiger Woods and Phil Mickelson paired together at US PGA Championship

The long-standing American rivals are both former winners of the event and will begin their challenge for the fourth and final major of the year at 08.35 local time (13:35 BST) at Valhalla on Thursday.

Woods - a four-time champion who won his first US PGA title at the Louisville course 14 years ago - and Mickelson, who won the trophy at Baltusrol in 2005, will be joined by 2008 champion Padraig Harrington.

In-form 2012 US PGA winner Rory McIlroy, fresh from his success at last month's Open Championship, tees off alongside reigning Masters and US Open champions Bubba Watson and Martin Kaymer - who won the US PGA four years ago - at 13:45 local time on Thursday.

Last year's winner Jason Dufner gets his title defence under way at 13:55 local time, with the 37-year-old set to play with Keegan Bradley and YE Yang - winners of the event in 2011 and 2009 respectively.

Other groups include world number one Adam Scott alongside Lee Westwood and Jordan Spieth - teeing off at 08:15 local time on Thursday - and Sergio Garcia, who leads the WGC-Bridgestone Invitational by two shots at the halfway stage, with Tom Watson and Steve Stricker at 13:25 local time.