Tim Henman has hit out at the critics calling on Roger Federer to hang up his racquet.
The Swiss will hope to end what has been his worst season for a decade on a high at the Barclays ATP World Tour Finals in London this week.
It is a tournament Federer has won a record six times but it would be a brave call to back him to make that seven.
The 32-year-old has won only one title this year, made one grand slam semi-final, and for a long time looked like he may not be at the O2 Arena.
Federer has also had to listen to people inside and outside tennis speculating on whether he should retire rather than risk tarnishing his phenomenal record.
Federer has always said he would like to play on until at least the Rio Olympics in 2016, and Henman sees no reason why his old friend should stop.
The former British number one told Press Association Sport: "It's definitely been harder for him but that's the reality when you're 32.
"When he was working with (former coach) Paul Annacone I used to speak to Paul quite a lot and he was always incredibly positive about Roger's work ethic.
"When you still have that level of ability and you've achieved what he has, it would be foolish to write him off just yet.
"He still has a massive passion for the game. You realise when you get older that it's not a real job and you've got to make the most of it.
"For people to even speculate or suggest that he should retire is ridiculous. He's earned the right to play for as long as he wants, and while he's still enjoying it then why not."
Henman plays occasionally on the seniors tour these days and on December 4 will be at the Royal Albert Hall for the Grand Opening of the Statoil Masters in support of children's charity Best Beginnings.
Henman retired just after his 33rd birthday, and he recalled the moment two months earlier when he realised his time had come.
"I recognise it's not necessarily the easiest decision to make but I knew it was the right time," he said. "I was in Washington and I'd just played John Isner and I'd lost 4-6 6-4 7-6.
"I was with Paul (Annacone) and I said to him that I wasn't sure I was enjoying it. He said if I wasn't enjoying it then I shouldn't do it.
"I'd never even contemplated retiring but it was like a light going on and I knew it didn't want to do it any more."
Federer at least appears to be finishing the season strongly, and he will begin his London campaign on Tuesday with a blockbuster round-robin clash against Novak Djokovic.
The first session on Monday afternoon sees Tomas Berdych face Stanislas Wawrinka before Juan Marin del Potro plays Richard Gasquet.