Lee Trevino once remarked the definition of pressure is playing for $5 a hole with only $2 in your wallet.

Continuing this ‘money in the wallet’ theme Golf Digest came up with a great piece and quizzing some of the world’s top golfer’s as to how much money they carried in their wallet.

However before revealing who carries how much and so on, New York University researchers raised alarm in identifying 3,000 types of bacteria overall by analysing genetic material on 80 $1 US bills.

The most prevalent species they found is one that causes acne. Others were linked to gastric ulcers, pneumonia, food poisoning and staph infections, the scientists said. Some carried genes responsible for antibiotic resistance.

Now putting aside those images in your mind, the question was asked of a handful of leading Tour players if they knew exactly how much money they had in that wallet.

While answers ranged from a few dollars to even around $1,000, five-time Major winning Phil Mickelson knew precisely the amount in his back pocket – $8,100.

“I’ve got $6,500 in $100s and $1,600 in $20s,” he said.

“I want to take care of people.  You shouldn’t be expecting stuff for free.  If someone does something for you, you should take care of them.”

The recent passing of Scottish caddy Dave Renwick revealed that Aussie golfer Steve Elkington ‘tipped’ Renwick $100,000 of his $360, 000 1995 PGA Championship winning purse but whether ‘The Elk’ took the money from his wallet we’re not sure.

However fellow Aussie Adam Scott reckons he has usually between $300 to $400 in his wallet, and like Mickelson this is mainly for tipping the likes of locker-room staff.

“I never used to carry that much, but spending a lot of time in the US, I’ve become used to the tipping culture,” said the 2013 Masters champion.

“I like it actually. It’s one of the best things about America.  It works well, I think.

“I like the feeling of looking after someone, safe in the knowledge that someone else would look after me in similar circumstances.”

Golf Digest also established 2015 Open winner Zach Johnson usually has between $100 and $300, Stuart Appleby had “a couple of hundred bucks” and golf instructor Hank Haney had $556 – although he said he “probably doesn’t need anything more than $20 and a credit card.”