Speaking ahead of their Carabao Cup semifinal first-leg clash with Arsenal, Rosenior was asked if winning the trophy would be a great early filip to his Chelsea career.
"If you don't take care of the next game, those trophies don't exist," he said.
"So, all I'm thinking about is winning the next game. I felt that against Charlton. I feel that about Arsenal. And after that, I'll feel that about Brentford.
"I'm focused on the moment. I'm focused on putting on the best training sessions, the best meetings, the best advice, the best information I can to win the next game. Because honestly, finals and trophies don't exist if you don't take care of the now."
On the ruthlessness of Chelsea's board, Rosenior insists he made the move from Strasbourg with eyes wide open.
"I'd love to be here for six years and longer, but I'm aware for that to happen, I need to win," said Rosenior.
"I understand every club has a different project and the word 'project' comes out a lot now in football, but the idea in any project is in every game you play, you're trying to win it. It's as simple as that.
"So, yes, I've got ideas about what I want the team to look like in a year's time, two years' time, three years' time. But I think I've got enough resources and enough tools with me now to win now. I've made that clear to the players. So, we're going to give it our best shot on Wednesday.
"The lads trained very, very well this morning and I'll make a decision on the team in the next few days and hopefully we go and attack the game."