Rob's father Bill - from Tylorstown in the Rhondda - became West Ham physio in 1958 following a wartime career with the Royal Engineers.
Six years later Rob joined him as his apprentice, and together they treated the Hammers' stars who would go on to form the backbone of England's 1966 World Cup-winning team.
But '66 would prove a bitter-sweet year for Rob, as just weeks after father and son watched club legend Bobby Moore lift the trophy for England, Bill died suddenly.
Rob - now 77 - took over as head physio, and in his time at the club he has seen them win three FA Cups and a European Cup Winners Cup.
"When dad started out we worked from a flat above the sports shop Bobby Moore used to run," said Rob.
"As a young lad my mates couldn't believe we had Bobby, Geoff Hurst and Martin Peters just popping up for a cuppa, but it seemed normal to me.
"Wonderful memories I have... and some bad ones too mind. I suppose you'd have to say the World Cup sticks out in my mind.
"Dad and I were due to go but the team doctor wouldn't have it; he said dad was too ill with his heart.
"But if I had to pick one memory, it would be beating the Arsenal in the 1980 FA Cup final. We had history with them, and it was lovely to finally get one over on them."
As well as footballers, Rob has treated East End boxers including Johnny Claydon, Charlie Magri, and most famously of all, Frank Bruno.
He stood down as first-team physio in 1990 after 1,750 matches.
But that was not the end of his association with the club, as he has continued running the clinic for the local community and ex-Hammers stars including Trevor Brooking, Billy Bonds and Frank Lampard Sr.
Rob says if he had his way he would carry on but added: "The wife says I've got to pack it in, at 77 when am I going to start taking it easy? So that's that, the boss has spoken.
"Mind you, I'm not a DIY or gardening person, so after I've caught up with my reading and walked the dog a bit, she'll probably be sick of me under her feet and will be begging me to go back."
Rob was treating his last customers up until kick-off on Saturday.
On Monday morning, builders will begin converting the clinic, opposite the main gates of the stadium in Green Street, into new flats.
When the final whistle went at Upton Park on Saturday, it did not only seal West Ham's Premier League win over Sunderland, but also marked the end of Welsh physiotherapist Rob Jenkins' 51 year association with the club.