Pedro Neto was sent off after receiving two yellow cards in three minutes during Sunday’s 2-1 defeat to Arsenal, marking the Blues’ seventh sending off in the Premier League this season.
Under Rosenior’s seven-game tenure, the Blues have finished with ten men in consecutive matches, following Wesley Fofana’s dismissal against Burnley last weekend.
“It’s been the same story for the last three games,” Rosenior said. “You have performances to get results and it’s the same story.
“It’s the same story in the ascendancy in all three games. What I never do, win or lose a game, is start pointing the finger at players, but it is clear what we need to improve.
“It’s not our football, it’s not our attacking play. We need to make sure we are ruthless in both boxes. To concede two goals from corners and get another red card, that has been the story of our season and it’s been the story of the last few games.
“I have respect for the previous manager Enzo (Maresca). I don’t speak about what happened before, but it is starting to happen with me. That’s something I felt we had addressed. We went 10 games without a red card, now two in two games and that’s a problem we need to solve.”