Dennis is tiring of the constant stream of comments from the Ulsterman since he became Ferrari's No 1 driver, following Michael Schumacher's accident at the British Grand Prix. "Eddie should spend his time focusing on his own performance and trying to get the best out of his team rather than making remarks that are counter-productive to that process," Dennis said.
As a result of Schumacher's injury, which has ruled him out for the next six weeks at least, Dennis believes McLaren-Mercedes must now be favourites for both the constructors' and drivers' titles. McLaren are just two points behind Ferrari in the constructors' championship, while Mika Hakkinen leads the drivers' standings by eight points from Schumacher and Irvine.
"We've got a far more realistic package now in speed and performance to win the championship, with or without Michael Schumacher," Dennis said. "But Michael is a very competitive individual and with him not being around, it will make life easier."
Irvine is confident he can see off the challenge of his new team-mate Mika Salo and spearhead Ferrari's bid for world championship glory. Irvine will be partnered by the Finn for the first time in Austria this weekend.
Salo has significant grand prix experience, including a stint at British American Racing this season in place of Ricardo Zonta. But Irvine believes Salo will be unable to match his pace.
"Mika does not make a lot of mistakes," said the 33-year-old Irvine. "He does not go off the road a lot, but that's not what Formula One is about. Formula One is about being fast.
"Mika, potentially, could be very good and it is a great opportunity for him. He has never been in a top team, never had that opportunity. I have not really spoken to him yet, but it is not going to be easy for him. It's difficult coming into a top team and being expected to go fast straight away."