Published Friday, 09 December 2011
Between them, the pair have racked up earnings of over £6m on the European Tour this season and either one of them could still top the European money list.
If McIlroy wins the final event - the Dubai World Championship - and Donald is in a two-way tie for ninth, their respective earnings would be £3,430,138 and £3,430,141.
"It would be foolish of me to rely on him not winning," Donald admitted.
"I know what's at stake and it's a big deal to me.
"There's certainly a lot of pressure. I'm still making a few mistakes - maybe because of what's at stake. When there's a lot on the line you feel more nervous, but sometimes it's a good thing."
US Open champion McIlroy, 22, was chasing leader Alvaro Quiros on Friday, while Donald continued to battle just outside the top ten.
"I'm not 100% and if it doesn't happen, it doesn't happen and there's nothing I can do about it," McIlroy said.
"You can just go about your game and try and play as well as you can.
"I definitely don't feel invincible, but I feel like every time I tee it up I've got a good chance of shooting a good score."
Donald, with the PGA Tour number one spot in America already in the bag, needs a top-nine finish to make sure of an unprecedented US and European double.