Joao Pedro scored twice as Chelsea won 3-2 to reach the Champions League round of 16.
Rosenior remarked afterwards, "I think the most pleasing aspect was the collective mentality of the group to have a positive reaction to a difficult first half.
"To get through in this competition is the most important thing. I'm delighted to do it in this way, in terms of our season, in terms of my time on the pitch with the players, that's going help us so much.
"I'm so proud of the players. Even in the first half, I'm asking them to press and a completely different way, a way they’ve never done before and hardly had any practice at.
"So that time over the next few weeks will help us get better and improve, but we still need to win games in this moment.
"I’m trying to do the very best I can with my group, with my stuff, and hopefully we can have more, really good nights like this."