The pair were together at Old Trafford in the 1960s and Ryan, who retired in 2012 after more than 20 years of service to the Reds, remembers his fellow Scot's prodigious work ethic.
"I was there training at The Cliff when he arrived," explained Ryan to ManUtd.com. "Of course, he came from near me as Falkirk is 10 miles away from the village where I grew up.
"He was a defender and quite a straightforward and dedicated player. He always trained very, very hard and that's one thing that sticks in my mind about him. He was always leading the shuttle runs, even if it meant he was collapsing by the seventh or eighth race. It's not an easy thing to do, lead from the front, so you knew he trained really hard. He was quite shy but determined to be really fit.
"I'd left to go to America by the time he went to Dundee United so I couldn't really follow his career but I did know he had gone up there to play in Scotland. I think he had a good career up there.
"It's very sad. I last spoke to his wife about him probably six or seven years ago."