Westwood, who led the Order of Merit for four months until Montgomerie overtook him at the German Masters last week, is now pounds 112,000 behind the burly Scot with just this week - and the Volvo Masters at Montecastillo at the end of the month, to complete the Tour schedule.
Montgomerie, the European No 1 for the past five years, is resting this week, but with a first prize of pounds 66,660 on offer at the Belgacom Open, Westwood, even if he won the event, would still be pounds 45,000 behind his rival.
But, as he said yesterday: "Monty's withdrawal is good news for me. It obviously means he can't get any further away and a good week for me means I'll be within reasonable striking distance."
Westwood won the Volvo Masters last year and says: "If I win this week and retain my title in Montecastillo I'm European No 1 no matter what Monty does. It's going to be difficult, but it's possible."
The 25-year-old Worksop golfer has been going through a lean spell in recent weeks but finished joint sixth at the German Masters on Sunday. "That was a good result for me," he said.
"I hadn't had many good finishes recently so it was nice to make a birdie at the last. It earned me about pounds 11,000 more than if I had made par. Of course, I'd like to win the Order of Merit. It wasn't a main priority at the start of the year, but it's become a priority as the year's gone on because my chances of winning it have increased.
"But I'm only 25 years old and hopefully I'll have few more chances to win it yet. If I don't do it this year I won't be too disappointed."
The Irishman Darren Clarke, lying third in the European money list, just over pounds 31,000 behind Westwood, withdrew from the Belgacom Open yesterday.
Clarke has been frustrated recently by playing superbly from tee to green and then not taking many of the chances offered by his fine approach play. He wants to concentrate on the Dunhill Cup at St Andrews and the World Matchplay.
One player who might concern Westwood is Nick Faldo, who won the tournament the last time it was held in 1994. Faldo finished sixth at the recent Lancome Trophy in Paris and is running into better form.Reuse content