Frank Lampard believes life in the Championship has made Mason Mount a better player after his first hat-trick in England earned Derby a 4-0 victory that pushed Bolton to the brink of relegation.
The on-loan Chelsea midfielder, who spent last season at Vitesse Arnhem, took his tally for the season to 10 with another eye-catching display.
Lampard said: "He did well in Holland last year, but it's not the competitive nature of the Championship I believe.
"I think he has developed here this season and there will be some testers for him. The game at Blackburn in midweek was physical, it was a test and it won't always be easy to show the attributes he did today.
"He has to take the rough with the smooth, but I believe he has improved and I also believe there is a lot more to come from him.
"When we had a little break in play I said to him he needs to start turning and facing people up, because people will struggle to deal with his quality, his quick feet, his awareness to play the ball around corners and that's exactly what he did.
"Mason missed two months of the season and that shows he's a boy that's going to score goals and that's important for us. We haven't got the centre-forward that's scoring 25 goals, so we have to contribute from other areas."
Mount and Craig Bryson broke Bolton's resistance in the closing minutes of the first half and the result was never in doubt from then on.
Bryson scored from a tight angle in the 37th minute and Mount finished off a one-two with Martyn Waghorn in the 45th.
Bolton carried little threat and only some fine saves by Remi Matthews prevented further damage, but Mount headed his second in the 55th minute before firing in from Ashley Cole's weighted pass eight minutes from time.
Derby moved to within two points of sixth place with victory and Lampard said: "The next two games are huge for us."
Crisis club Bolton in contrast look destined for League One and manager Phil Parkinson admitted he will be glad when a season of turmoil both on and off the pitch is over.
"It's been tough for us and it's horrible to get beat," he said. "As a manager, coaching staff and players you live off results and when you get beat like we did today and compound that with the problems we are facing it's a pretty low place.
"But we've got to make sure we pick ourselves up and finish the season as well as we possibly can.
"Derby are a good side, they are a team that when they get in front, especially at home, and start playing with confidence they have got probably as good final-third players as anyone else in this league.
"We were in the game and I could feel the crowd maybe starting to get a bid edgy. The goals were good from their point of view, but we've let runners go and against a team of that quality you get punished for that and I felt we did today."