Gerrard saw a noticeable difference to how Chelsea performed under predecessor Liam Rosenior.
He said on TNT: "I was impressed with Chelsea in the second half with their game management. A clean sheet, better structure to their game and lots of positives.
"Chelsea were much improved, to a man. (Enzo) Fernandez will get the headlines for his winning goal, but across the board, the structure of the team was much better.
“There was a lot more fight and a lot more passion within that. I thought Calum got his game plan spot on.
“Leeds will go away from this game full of regret, really. They never really got going until the second half. They had one good chance either side of half-time, but that's not enough in a semi-final if you want to knock Chelsea out."