"I went up there for a day and it really went well," the signal caller said. "I liked how the campus was and how close it is to home for me.
"I love how they are getting bigger and growing the program with Coach Monken.
"I really like Coach Monken a lot. He was honest with me and is after me hard and that means a lot. Also Hattiesburg has some amazing food so that's a big bonus."
Rosier was first spotted by Coach Arroyo, who watched him throw at a practice and extended an offer.
Since then, the relationship has continued to grow.
Rosier has plenty of suitors right now, as he also has offers from Arkansas State, Furman, Miami (FL), Middle Tennessee, Northern Illinois, and Western Kentucky in addition to Southern Miss.
Rosier said he plans on camping at Auburn, Alabama, and Southern Miss among a few others this summer.