Cape Town - Former Springbok coach Andre Markgraaff believes South Africa's Super Rugby players are not mentally strong enough to deliver the goods on a consistent basis.

In an interview with Netwerk24, Markgraaff said the Bulls' recent 56-20 home defeat to the Chiefs and their 22-20 loss to the Jaguares this past weekend were inexcusable.

Those losses came after the Bulls had achieved impressive wins over the Lions and Sharks.

Before the Chiefs game, the Bulls beat the Lions 30-12 in Johannesburg and the Sharks 37-14 in Pretoria. They also beat the Sharks 19-16 in Durban before coming unstuck against the Jaguares.

"It's been a problem in our rugby for years. Our teams will deliver a fantastic performance one Saturday but can't keep it up. After so many years of professional rugby we're still not over the mental barrier. I have no doubt that overall our players are mentally soft," Markgraaff said.

Markgraaff, who coached the Springboks at the dawn of professionalism in 1996, said it should have been "impossible" for the Bulls to lose by such a margin to the Chiefs and added that the Jaguares should have been "beaten by 25 points" at Loftus Versfeld this past weekend.

The Bulls led 20-10 heading into the final minutes before two late tries from Jaguares replacement flyhalf Domingo Miotti stunned the home crowd.

Markgraaff was a renowned coach of Griquas and also had a stint as coach of the-then Cats franchise in Super Rugby.