Leclerc leads Vettel in the drivers’ championship by two places and 19 points with just two races remaining in 2019, the Monegasque’s first season with Ferrari.
The 22-year-old has displayed his talents by taking seven pole positions so far this season, a tally that no driver will beat as his nearest challenger Valtteri Bottas has five.
Ferrari began 2019 with Vettel given “priority” over Leclerc, although his performances have undone that, with confusion reigning as to how the Scuderia should progress.
But Irvine, who partnered Michael Schumacher at Maranello in the 1990s, is of no doubt that Ferrari should anoint Leclerc as new team leader.
“I thought Leclerc had a good chance of beating him because I don’t think Vettel is a worthy four-time world champion,” Irvine told Betway.
“I think he is a very good driver, but he makes a lot of mistakes and I never really thought he was that fast.
“We saw it with Daniel Ricciardo and we’re seeing it again now. Vettel got an amazing deal with Ferrari. I was surprised because it was at a stage where he was getting destroyed.
“I think Ferrari have to focus on Leclerc. We’ve seen this season Vettel not being sacrificed because he is a four-time world champion – they’ve lost wins because of it.”