Fotuali'i arrived at the Liberty Stadium in 2011 and left two years later for Northampton Saints, starting 25 PRO12 games during that time compared to Webb's 22.
And since the Samoan international moved on, Webb has gone from strength to strength with the Ospreys.
The 26-year-old has won nine of his 12 Wales caps since Fotuali'i left, scoring four tries in his last six appearances.
That eye for the line is also apparent in the GUINNESS PRO12 - with seven tries in nine league games this season only Ulster's Craig Gilroy has more - and Webb believes his ex-teammate helped a great deal.
"I learned a lot from Kahn when he was at the Ospreys," said Webb. "His running game is very good and I used to pick his brains a little bit. It is paying off now.
"You just have to pick your moment, really. You can't do it all the time. It is about being smart and picking the right time to go."
Webb's next test is an Ireland side that has won ten matches on the trot and boasts a pair of world-class half-backs.
However, he is relishing the prospect of going head-to-head with Munster scrum-half Conor Murray this afternoon.
He added: "I played against him earlier this season when the Ospreys played Munster, and you look forward to testing yourself against British Lions and some of the best players in the world."
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