The former Springbok fly-half was renowned for his kicking during his two years in the green and gold jersey.
Now he is helping two of Australia's biggest stars hone their kicking skills. Both Cooper and O'Connor have established themselves in the Wallabies side in recent seasons and could face the Lions during the 2013 tour.
Van Staaten has been working with all of Australia's kickers over the past weeks and will link up with Cooper in Cape Town ahead of Queensland Reds' Super Rugby tie with the Stormers.
"I've worked with them over the internet week by week and I analyse all their kicks from the weekend's matches and look to sort out any problems over the internet with some very good software," said Van Straaten.
"Quade has been fantastic and we've developed a good relationship and he's got so much talent that it's scary.
"I'll do some analysis with him at the hotel and then also on the field, and we have some high speed cameras to show him what he's doing right and how his striking improves kick by kick.
"He's probably the player who has improved the most of all the Australian guys I've worked with and although he still makes one or two mistakes we'll look to rectify any little problems on Wednesday."
Van Straaten has also singled out O'Connor for special praise. The Wallaby wonderkid had a nightmare with the boot during Western Force's loss to Melbourne Rebels on the weekend.
But the former South African pivot is adamant that O'Connor will become the world's most accurate kicker.
"James had a bit of a hiccup on the weekend, but that can be easily rectified and I'm busy with some analysis for him because he looked a bit shaky on his approach," added Van Straaten.
"I believe James is going to be the best kicker in the world for the next 15 years."