A week after Rory McIlroy ended Luke Donald's 40-week reign as world No. 1, the young Northern Irishman could be overtaken by the two players ranked below him at the World Golf Championships-Cadillac Championship.
If Donald, who currently ranks second, wins on Sunday he regains the top spot. The Brit must finish among the top four in this elite field to have any chance of unseating McIlroy.
Westwood, the current No. 3, must win to have a shot at regaining the top spot he relinquished to Donald last May. If he wins, he would pass Donald and get to No. 1 if McIlroy finishes worse than third at TPC Blue Monster.
The three are playing together during the first two rounds of the Cadillac Championship.