Losing ground out on track and in the points led to Renault “desperate” protest against Haas, says Guenther Steiner.
Haas will face the FIA courts on November 1st having launched an appeal against their disqualification from the Italian Grand Prix.
Romain Grosjean finished the grand prix in sixth place but was thrown out of the results when Haas’ floor was found to be illegal.
The FIA looked at the floor after Renault protested.
Steiner believes it was born out of desperation as they are falling behind out on track.
“I just see their performance has gone down, I don’t know what’s going on internally,” said the Haas team boss.
“For sure they dropped their performance, and their engine they make themselves so they can have nobody to blame.
“If they confuse themselves even more, it’s better for us – I’m not against it!
“You could see that they were a little bit desperate when they put the protest in against us in Monza.
“They’ll try anything instead of focusing on themselves to get better.”
With four races remaining this season Haas trail Renault by eight points in the race to finish the season best of the rest.
“It’s still difficult,” Steiner admitted. “I know we have four races to go.
“They were not very strong this weekend [at Suzuka] but they were luckier than us and scored a point but their performance and their pace was not good.
“But that doesn’t mean that they’re not going to be good in Austin and Mexico.
“We need to have our guard up and do a good job. We are not there yet.
“We will fight but there’s still a long way to go, still four races, still 20% of the championship.”