Speaking in the wake of last Sunday's Styrian Grand Prix, having finished three laps down on race winner Max Verstappen, Mazepin complained that his car felt "very heavy" and that this had left him a "sitting duck".
"It was very lonely," he said of his race, "I felt like a carrot that was about to be caught by a rabbit. Unfortunately I was caught, and then eventually I was also caught by the lapped cars and ****** hell when you get through to being lapped you lose your tyre temperatures, you go onto the dirt and it really is very painful.
"I was thinking when I was driving in the car that if there's one thing I can ask for Christmas it's just to finish on the same lap as others," he added, "because that's just not a clean race at all. Once you get caught by that train of cars it's just a never-ending spiral which is very painful for a driver, so just one of those days...
"When you get lapped on a reasonably short circuit like here there are loads of marbles off-line and the rule is you have to let the cars overtake you on the racing line which means you have to go off the racing line and then when you go to brake it's a bit like ice."
"There is a small weight difference depending on the weight distribution," Steiner told reporters today ahead of this weekend's Austrian Grand Prix. "Heavy is never good, but it is not like 20kg heavy, or even 10kg heavy, it is nothing like this.
"The chassis, they are a year old," he continued, "they've raced for a year, and normally every year you make a new one, and for sure the chassis never get lighter over the year.
"Obviously a heavier car never makes you faster, really, you know. I stated the obvious here. But how much, as I said I don't want to go to the exact amount of weight, for sure it does something, physics are physics you know, we will not change them, so it slows him down, but it's not a lot."
Last weekend, Mazepin suggested that it could be "six or seven" races before he gets a new chassis, but Steiner said it could be as soon as the Belgian Grand Prix once the season resumes after the summer break.
"The chassis is planned to be with us after the summer break," said the Italian.
Referring to the Russian driver's complaints about being lapped, Steiner said: "He got caught by the cars which were lapping him - we are the lapped cars obviously - and that makes you a sitting duck. Once you let three cars by your tyres go where you don't want them to be and you never get them back.
"I don't think that has anything to do with the chassis" he insisted, and that strategy (mediums to hards) was done because again, in the beginning, we decided to give him an earlier pit stop to keep him out of the blue flags. So I wouldn't put that one down to the weight difference."
Check out our Thursday gallery from Spielberg, here.