London Irish director of rugby Brian Smith says of all the players he has coached, "they don't come any finer" than Exiles captain Declan Danaher.
Danaher is set to make his 250th appearance for the club on Sunday.
Smith - who has coached George Gregan, Stephen Larkham and Jonny Wilkinson - rates the forward as highly.
"When I quit coaching I will be comfortable in using his name in the same breath as Gregan, Larkham and Wilkinson," Smith told BBC Berkshire.
Danaher, 32, will become one of only three London Irish players to make it to 250 caps and will do so against Premiership champions Harlequins.
And Smith paid tribute to his captain - who made his debut in 1999.
"He is an unbelievable character of integrity," said Smith.
"It's not just important to be a good rugby player, it is important to be a good person and they don't come any finer then Dec Danaher."
Danaher, who has suffered a string of injuries throughout his 13-year career, admits he did not think he would make it to 250 and says there will be a tear in his eye as he leads out the team at the weekend.
"It is a significant number and it is a great milestone to get to," Danaher told BBC Radio Berkshire.
"If it hadn't been for a couple of knee injuries I probably would have had a couple more."
Danaher added: "I remember cap number one at Northampton away and I got 10 to 15 minutes at the end and it was brilliant and a lot of fun.
"You don't forget days like that. I remember my 100th against Sale, my 200th was a miserable trip to Italy where I'd been sick all week."
Danaher says he has several highlights from his lengthy career including the Powergen Cup final in 2002 but the Heineken Cup semi-final in 2008 stands out.
"The semi-final against Toulouse at Twickenham was the game I enjoyed the most. We were so close to making the Heineken Cup final and the atmosphere was fantastic. Being older I enjoyed it a lot more.
"We'll see how the body is feeling in a couple of years and maybe I might make 300."