"Things outside of the field do not come into it. If you are worried about various outside influences then you won't be sitting here," Coetzee said.
"I think Steve isn't stupid, he has done well and handled pressure games in the Tri-Nations, many international games. So we are looking forward to a good game.
"To be honest we don't look at the refs, we focus on what we have to do. It is out of our control completely. We just make sure that we prepare well for this semifinal."
South Africa actually has a good record when Walsh has been the whistler, going 6-1-1.
The last time he refereed the Boks was in May, when they crushed England 58-10 at Bloemfontein.
Coetzee added the Boks could be helped by Walsh because of his familiarity to South African teams and their style of play.
"We did feel in our match against Fiji that there were problems at the breakdowns and the Fiji flankers were allowed to hang off the scrum which allowed them to add numbers at the breakdown," Coetzee said.
"Because Walsh is a referee the guys have played with often there shouldn't be a problem with the approach at the breakdown as everyone knows what Steve is about.''
However, Walsh is no stranger to controversy.
The 35 year old was suspended for three days at the 2003 World Cup for clashing with England fitness trainer Dave Reddin when England had 16 men on the field near the end of a tense match with Samoa.
Walsh was also suspended from international duty after the 2005 British Lions complained about his behavior in a New Zealand tour match.
In this year's Six Nations, Walsh was castigated for leaked remarks to Wales about how Ireland play tackle ball.
The International Rugby Board (IRB) came out in defence of under-fire World Cup quarter-final referee Wayne Barnes on Tuesday.
Englishman Barnes has received criticism from New Zealand rugby chiefs and the country's media and been subjected to personal abuse and death threats from fans on internet sites after the All Blacks lost 20-18 to France in Cardiff on Saturday.
"The IRB believes the standard of refereeing is the highest it has ever been at a Rugby World Cup tournament.
"The criticism of referee Wayne Barnes following the France versus New Zealand quarter-final match on Saturday 6 October is completely unwarranted," the IRB said in a statement.
New Zealand Rugby Union chairman Jock Hobbs told Radio New Zealand that two crucial decisions by Barnes had cost the All Blacks the match, the sin-binning of centre Luke McAlister and missing a forward pass in the lead-up to France's second try.