And he revealed he tries to play the sort of valuable role the sacked Chelsea boss had as a senior player with Albion.
Rosenior was targeted by Chelsea fans as their side went down 3-0 to the Seagulls and was axed less than 24 hours later.
Gross and Rosenior were colleagues in the former’s first season at the Amex, in 2017-18.
Although Rosenior then retired as a player, he remained at the club as a coach.
Speaking after Tuesday’s game, Gross said: “He helped me so much at the beginning here, feeling part of the club, feeling comfortable.
“He was a senior player at that time, like I am now, trying to help a guy who's coming from abroad and get to know everything.
“That's very appreciated from me and he's such a good man with a nice heart.
“I can speak about a human being and I just wish him all the best.
“It's not easy, the Premier League, but I think he will be fine.”
Gross quickly grew to love Albion and the Brighton area and is delighted with his mid-season decision to return from Dortmund.
He said: “I feel so comfortable here. I love my life here. My family loves it.
“Like my kids, I feel really comfortable, that helps.
“I know that there are so many good people here.
“There are so many good people I knew from before, team members, staff members.
“We do a lot off the pitch. I try to just be a really good team member and I think we are a strong team.”