The Blues put in a much-improved performance against Leeds at the weekend to reach the FA Cup final but the defender says that the squad is culpable for the woeful results that saw Rosenior axed last week after just three months in the job.
Chalobah said: "No matter what manager goes, it's difficult. You spend time with them, working with them every day. You have to adapt, you've got to reset again. We can use that as an excuse, but at the end of the day we've got to look at ourselves as players and take responsibility."
The Chelsea ace is hopeful that the determined performance against Leeds can be replicated for the remainder of the season under caretaker boss Calum McFarlane.
Chalobah said: "When things aren't going your way, that's what we keep hold of. We've shown it in parts of this season. It was just the same conversation today. We need to show our mentality, our winning habits and winning spirit.
"It's the hunger and determination. Wanting to win second balls, wanting to win headers. Those little things are what's needed. When we do that, our quality shows.
"Maybe when you don't win games, it's hard to get that determination back. It's just resetting, getting our standards back. It's still the same players we had at the start of the season when we were flying. It's not like we lose our abilities overnight. It's just resetting and getting that feeling back, that mentality back.
"The past is the past. For us, it's about results. We need to be winning games. That's what the fans want, it's what we want, it's what the club wants. What's happened has happened. We just have to look forward."