Joao Pedro and a Cole Palmer penalty had the Blues 2-0 ahead before the hour mark, but then Leeds fought back to earn the point through goals from Lukas Nmecha and Noah Okafor.
Rosenior remarked afterwards: "It was two key moments in the game that we didn’t take care of, when we didn’t stay calm.
"Moi Caicedo’s a magnificent player, he’s been top for me, but he makes a poor decision. How the play gets there as well, we made a few poor decisions in terms of how we press in that moment and we give away a penalty.
"The penalty goes in, they hit a few long balls, their energy is up, they pick up a few second balls. The player handballs it, it affects my players in that moment, they think it’s a handball and switch off and don’t clear the ball, they score.
"Then for 25 minutes after that it was wave after wave of attack, but we couldn't find the goal. We have to just make sure we take care of those moments and be professional. I don’t think it’s about reacting to set-backs. You’re always going to have a spell in the game when you’re not on top.
"The ridiculous thing for us is that they’ve managed to score two goals in a five-minute period, when for the other 90 minutes of the game we were by far the better team. We just made poor decisions in key moments."
He also said: "If we can just focus and concentrate for 90 minutes, this team has unbelievable potential, which you saw for probably 90 per cent of the game today. I feel like I already know what I want to work on to improve that, it’s just making sure we get the time to do it."
Meanwhile, Rosenior admits fullback Marc Cucurella suffered a hamstring after being forced off at halftime.
He confirmed: "Unfortunately at half-time he felt his hamstring. It wasn’t a tactical change, it was one that was enforced.
"Cucu’s been top and hopefully he’ll be okay. We’ll scan him and make sure we find out if he’s available for the next game."