But Mosca would also get under Barrow's skin by being too aggressive. One of the most controversial plays of Mosca's 15-year career came in the 1963 Grey Cup when he hit B.C. running Willie Fleming out of bounds, completely overshadowing the Ticats' 21-10 victory.
"I think I drove John wacky at times because sometimes I played beyond the means," Mosca told The Canadian Press in a telephone interview Wednesday.
Barrow died Tuesday at the age of 79. The Ticats said Wednesday the cause of death wasn't immediately known.
Mosca said his edgy play would prompt Barrow to pull his teammate aside.
"He did but I told John, 'You play your game and I'll play mine,'" Mosca said. "There was no sugarcoating with our defence.
"That's the way we played and that's the way we gave it to you."
"It is a very sad day because a piece of the team has gone," Mosca said. "John played very physical, the way I played.
"I had the pleasure to play alongside John for 10 years, in which we worked hard, played physical and accomplished great things. John was a friend, he was a pretty fair guy."
The six-foot-two, 255-pound Barrow enjoyed a stellar 14-year career with Hamilton (1957-70). He helped the Ticats win four Grey Cups and earned CFL all-star honours on 11 occasions. Six times the two-way player was the East Division nominee for the league's top lineman award, winning in 1962.
The native of Delray Beach, Fla., was also named the CFL Lineman of the Century in 1967.
"One of the top players in the storied history of our league, John Barrow's accomplishments are something today's players can aspire to," CFL chairman Jim Lawson said in a statement. "His record is something fans from any era can marvel at, and his image is something those of us lucky enough to see him play will never forget.
"All of us at the Canadian Football League join his family, friends and former teammates in mourning his passing."
Barrow played in nine Grey Cup games with Hamilton. Mosca also appeared in nine CFL title games but eight were with the Ticats as in 1960 Mosca helped the Ottawa Rough Riders emerge victorious.
"John was quite a leader and teammate," said Mosca. "His voice in the locker-room was well respected while his play on the field was very tough."
Something Mosca learned first-hand playing against Barrow while with Ottawa (1960-'61) and Montreal (1962). Mosca returned to Hamilton in '63 and remained there until retiring following the Ticats' '72 championship season.
"John was tough," Mosca said. "He was very physical."
Barrow was inducted into the Canadian Football Hall of Fame in 1976 and added to the Ticats Wall of Honour in 2001. Five years later he was voted No. 17 in a poll by TSN of the CFL's top-50 players and in 2012 was named to the All-Time Tiger-Cats squad.
Barrow played collegiately at the University of Florida, earning first-team All-American and All-SEC honours as a senior. He was a fifth-round pick of the Detroit Lions in the 1957 NFL draft but came to Canada instead.
Barrow retired in 1970, then served as the GM of the arch-rival Toronto Argonauts from 1971 to '75. The club reached the Grey Cup game in Barrow' first season but lost a heart-breaking 14-11 decision to Calgary after the Stampeders recovered Leon McQuay's late fumble.
During Barrow's tenure, Toronto signed such players as McQuay, kicker Zenon Andrusyshyn, defensive lineman Jim Stillwagon and quarterback Joe Theismann. The Argos also claimed tight end Peter Muller (1973) and defensive back Larry Uteck (1974) as territorial exemptions.
But according to former Argo Mel Profit, Barrow wasn't exactly warm and fuzzy in his first meeting with the '71 squad.
"John opened by stating he felt he was in a position to bridge the gap that had existed between management and the players," Profit wrote in his book For Love, Money and Future Considerations. "In the next breath he told us that, inasmuch as we represented the city of Toronto, we had an obligation to present a 'respectable appearance' and since he didn't feel long hair was respectable, those present would have to get haircuts.
"He quickly assured us, though, the fact he wore a crew-cut had nothing to do with his decision. I sat there thinking: 'This is 1971, this is a group of relatively intelligent people and this isn't really happening. It was. A few minutes later he categorized everyone as a bunch of 'overpaid losers.' After that, I kind of lost interest in our new leader."