Luke Donald has been partnered with Rory McIlroy for the forthcoming Memorial Tournament in Ohio.
McIlroy lost his World number one ranking to Donald on Sunday after missing the cut at the BMW PGA Championship.
They both feature as part of a top-quality line-up, which includes seven of the current world top 10.
They could swap places again if US Open champion McIlroy wins and Donald finishes outside the top 13.