US Masters: The world number one spot will be up for grabs in this week's Masters - but only Phil Mickelson can take it off Tiger Woods.

Mickelson will achieve top spot for the first time in his career if he wins a third green jacket on Sunday and Woods is outside the top five.

The gap between the pair shrank during Woods' eight-month injury lay-off, but his victory at the Arnold Palmer Invitational two weeks ago - his third event back - prevented Mickelson having a chance to be number one at last week's Houston Open.

Sergio Garcia was also in the running at the WGC-CA Championship last month, but could not get the result he needed there and is now too far back to catch Woods this week.