Team defends Kovalainen amid rookie struggle
The pair both made their grand prix debuts in Melbourne, but while Briton Hamilton went on to record consecutive podiums in every subsequent race, Kovalainen has broken into the points placings just twice.
But "It's an unfair comparison," Renault's engineering boss Symonds said in his team's official podcast reviewing the recent Monaco grand prix.
The Briton said his 22-year-old countryman, Hamilton, had been "quite lucky" to make his initial mark in formula one with the championship-contending McLaren, while Renault have struggled to get to grips with its R27 car.
Symonds said: "Last year's McLaren wasn't that good, and I think if (Hamilton had) gone in last year it would have been a slightly different story."
He explained that Kovalainen, who replaced Renault's departed world champion Fernando Alonso this year, was conversely unlucky to have to debut with the difficult 2007 racer.
Symonds said: "If you go a little bit too far (with the R27), it can bite you, and it has bitten Heikki a couple of times — he had quite a sizeable accident in testing in Bahrain.
"It's the very last thing that a novice driver needs."