Kalas and Piazon were two of several Blues youngsters shipped out on loan by the Premier League leaders, and the pair have played key roles in helping Fulham sit seventh in the second tier.
Ex-Chelsea man Slavisa Jokanovic is currently leading Fulham's chase for a return to the top flight, with the Whites just five points off the playoffs.
And speaking at the 2017 London Football Awards on Thursday evening, Cairney heaped praise on both Kalas and Piazon.
"I just think they have made the squad so strong," said Cairney. "Kalas has been brilliant, especially at the start of the season. Lucas has just got a bad injury at the weekend but he is brilliant on the ball and has done well.
"We pass out from the back. It is risky football, if you make an error, don’t worry. You just have to keep on going and I think that’s why as games have gotten on we have got more and more confident and we are showing that at the minute."
Cairney was named EFL Player of the Year at the awards ceremony with the midfielder having also impressed in Fulham's hunt for promotion.
The 26-year-old saw off competition from his team-mate Sone Aluko as well as Queen's Park Rangers' goalkeeper Alex Smithies, Barnet's John Akinde and Scott Hogan, formerly of Brentford but now at Aston Villa, for the accolade.
He has seven goals and nine assists to his name this season, while he is also filling in for Scott Parker, who is playing out the last few years of his career at Fulham after an impressive career with England, Chelsea and Tottenham.
And therefore Cairney believes he is having the best year of his career to date.
"I think it is great [to win London's EFL Player of the Year]," he said in response to Goal at the London Football Awards. "It is great for me and my family and it is a proud moment.
"My form this season has been the best of my career so far, no doubt. The manager and the staff have played me in more of a central position and I have enjoyed every minute of it.
"I just think it is the change of position, change of formation, it just suits my game. I’m on the ball a hell of a lot, and I don’t know, maybe giving me the captaincy gave me a bit of extra responsibility in the roll. I owe a lot to [manager].
"I don’t know about taking over from him, he’s a legend [Scott Parker]. I am the captain when Scott doesn’t play. In terms of football we are playing some of the best stuff in the Championship with the passing game that we have.
"The results haven’t matched our performances sometimes and we have got to change that if we are to have a chance of getting into the playoffs."