The former Liverpool manager has branded the tournament the "worst idea ever in football".
An unimpressed Stoichkov has responded to the Red Bull football chief, telling El Mundo: "I didn't expect that from Jürgen.
"I have so much respect for him that maybe if he's a little angry it's because Salzburg aren't (any longer) in the competition because he's a director of Red Bull.
"When Liverpool were playing nobody complained, when they receive money nobody complains. I think we need to have more respect in these tournaments.
"I had the chance to play in it in the past, when it was just a few matches, but I think that both Gianni (Infantino) and FIFA have done something different. You bring together many cultures, new systems, new tactics, many different teams that didn't know each other before playing in a tournament like this.
"Everything is fantastically good. First of all, the fans have never been absent from the ground, except for one match where there were warnings of suspension due to thunderstorms. Yesterday Maresca (Chelsea manager, Enzo) also complained about the rain, but what do we do? Do we give Infantino a remote control to stop the rain? They complain about everything."
Why is Klopp complaining now?
On Klopp, Stoichkov continued: "They don't complain when they earn 20 million a year, they just have to wait and see if they play from Saturday to Saturday, without playing in the Copa del Rey, without playing in the FA Cup, without playing in the Carabao Cup. All those trophies they have that are worthless.
"Years ago they were worthless, because maybe they were in UEFA. Now in Spain they already have six teams in the Champions League. The same goes for England, the same for Italy. I have no idea what they're complaining about.
"Let's see, what would he prefer, to go play in China, Japan or Indonesia, or to play in a competition that gives you much greater prestige?
"Note that he also played in these tournaments with Liverpool in previous years. I didn't hear Klopp complain like that all of a sudden. Maybe he was missing other teams that Red Bull put forward to be there. It's an important tournament, a tournament where there are many young players who are also starting out, there are many players who give you this opportunity that you can play in a tournament."