"I think if you have played rugby long enough and you have read in the newspapers that you are not good enough at times, you have to pick yourself up. In fact, I think it will make our resolve even more."
Nobody in the Springbok team will know better about the loneliness of being at your worst and the highs of being at your best than du Plessis, who has resurrected himself from the bad form of Super Rugby.
So out of sorts was du Plessis in Super Rugby that there were calls for Springbok coach Heyneke Meyer to release him to the rugby wilderness but his performance in the past two weeks have helped to lessen the disappointments of losing to the Wallabies and All Blacks.
In both tests, du Plessis' premature departure from the field because of injury has had a catastrophic effect on the team, depleting experience in the side and on Sunday disabling a dominant scrum performance.
Du Plessis hit back at his critics, saying he heeded the opinion only of those who mattered in his rugby career and he was pleased his form - and that of brother Bismarck and Sharks prop Tendai Mtawarira - was coming right for the Springboks.
"It is a very lonely place if you don't have a successful season and it is easy to find mistakes and criticism. If you give me one guy who it doesn't affect then I will show you a liar. If you are a player you've had enough criticism in your life to be able to deal with it and to know whose opinion really counts.
"About the criticism, I don't think I doubted whether I have the desire and the skills. Unfortunately our season at the Sharks didn't go as planned and that was not because of a lack of trying. I'm happy we can play better when it matters the most."
Du Plessis' knee injury from Sunday is hopefully not serious enough to keep the veteran off the field for long and he should be able to resume training next week in the build-up to the Springboks' last Rugby Championship test against Argentina.
- Independent Media, South Africa