It would have been easy for Andy Murray to shirk the question when asked at his post-match press conference on Friday about the doping ban handed out to Viktor Troicki - the man he plays for a place in the Queen's Club final.
Just hours earlier, Murray's fellow Briton and London 2012 Olympic gold medallist Mo Farah denied he had ever taken performance-enhancing drugs, with Farah's coach Alberto Salazar at the centre of recent doping allegations.
The subject of Troicki's 12-month suspension - which had been reduced from 18 months on appeal - was put to the Scot following his victory over Gilles Muller.
At the time, Murray had called for "zero tolerance", labelling the Serbian "unprofessional" for claiming he was too ill to provide a blood sample following the 2013 Monte Carlo Masters.
Troicki has since rebuilt his career after serving his ban and has risen to No.25 in the world, seeing off John Isner in straight sets to book his place in the last four here, but Murray has stood by his previous criticism.
"Obviously it's a difficult situation," said Murray. "I said at the time you have to be aware of what exactly the rules are.
"Like I said, it's extremely serious. If you want to protect the image of your sport, you need to understand how serious the drug testing is and anti-doping is.
"I stand by what I said there. I'm sure he's learned a lot from that."
Murray is aiming for a record-equalling fourth Queen's Club title, and goes into Saturday's semi-final with a perfect 6-0 head-to-head against Troicki.
The British No.1 continued: "I think players now realise that it's extremely serious business, the drug testing. I know that I'm getting tested a lot more than I was in the past.
"It's something that needs to happen. If you want the public to take your sport seriously, you need to have strong anti-doping protocols and make sure that all of the athletes are getting tested as much as possible. And that's certainly happening.
"I'm not saying that it's perfect. I don't think any of the sports are. But you need more money, more investment in it if you want to have the best protocol possible.
"I don't know exactly where that money comes from or who is responsible for that, but I'm pro testing, as much as is required to make sure the sport remains as clean as possible."