The striker was surprisingly picked for his senior international debut earlier in November for the goalless draw with Saudi Arabia.
And Di Santo thinks his position ahead of Manchester City's Tevez is a reflection of the progress he has made under Wigan boss Roberto Di Matteo.
He is quoted as saying in the Daily Mirror: "When I saw my name in the squad list but Tevez's wasn't, it was a real surprise.
"It told me that what I was doing at Wigan was good. The gaffer has taught me many things."
Di Santo started as Wigan lost 2-0 to City in midweek, when Tevez remained as an unused substitute.