Paul Cook's men are welcoming the Saints at the DW Stadium on Sunday, having defeated Premier League trio - Bournemouth, West Ham and Manchester City to seal a last-eight spot.
The 26-year-old has played a vital role in Wigan's fairytale run in the FA Cup, featuring five times, scoring a goal despite missing the clash with Pep Guardiola's men due to a suspension.
And Morsy, who is the only Egyptian left in the competition, is aiming to inspire his League One outfit past Mark Hughes' men to secure a semi-final trip to Wembley.
“Mohamed Salah is great,” Morsy told the Mirror.
“He’s a world superstar, but he’s so humble and he always makes me feel comfortable.
“I’m the only Egyptian left in the FA Cup. We support each other whenever we play. It’s a chance for us to make history.
"The club won the [FA] Cup, but to get to the semis as a League One club would be some achievement.”
Wigan Athletic are gunning for their third FA Cup appearance at Wembley in five-year.