The sturdy London, Ont., native was matched from the beginning of camp with Sam Reinhart, a candidate to go first overall in the 2014 NHL draft, and 16-year-old Connor McDavid, the favourite to be the top pick in 2015.
It's too easy to say Horvat's job is to get them the puck, bang in their rebounds and hustle back if the play moves the other way, because Horvat is a nifty offensive player in his own right.
Nifty enough to be named MVP of the Ontario Hockey League playoffs with the London Knights and to be selected ninth overall by the Vancouver Canucks.
"I'm just trying to do my job keep it simple — do my job defensively and get them guys the puck," the six foot, 205-pound Horvat said Friday. "I go to the net and try to bang it in.
"If I play hard and play a two-way game, I think it completes the line."
The unit produced a raft of scoring chances in Canada's tournament-opening 7-2 victory over Germany on Thursday — so many that McDavid said he was embarrassed not to put at least one of them in.
Horvat and Reinhart each scored, while McDavid had an assist and ended up a team best plus-3.
Canada goes at it again Saturday against the Czech Republic, who fell 5-1 to the United States in their opener.
The Canucks must be pleased with coach Brent Sutter's decision to put Horvat with the young phenoms.
"For sure," said Horvat. "They wanted me to get a lot of ice time.
"They wanted me to keep improving on my pace, so for me to play with those two guys, there's a lot of pace and quick thinking."
There's a tendency to see Horvat as the veteran of the unit, but he's still 18, only seven months older than Reinhart, who is 14 months older than McDavid.
Sutter felt he had the kit of assets to bring the best out of a line that, despite its youth, gets lots of ice time.
"Bo plays in both ends of the ice," the 51-year-old coach said. "He plays a heavy game.
"He's a big strong kid. He's good on faceoffs. He's been well coached with Dale (Hunter) in London and he understands his responsibilities defensively. Those things to help two young kids like Davy and Reino are significant, even though he's still young himself.
"It's a young line, but it gives you a bit of everything. It gives you speed, size, intelligence and they're all for the most part responsible defensively."
McDavid is a dazzling playmaker, who creates scoring chances seemingly out of nothing.
Reinhart is clearly one of Sutter's favourites — a smart offensive player who can play well on both the power play and penalty killing.
"There's tremendous skill," Horvat said of his unit. "Not a lot of 16-year-olds can play in this tournament, especially for Canada.
"Connor's a special hockey player. He knows where everyone is on the ice and he thinks two plays ahead of everyone. Sam is also a really smart player. He can find you anywhere on the ice."
The Czechs also have a 16-year-old, Pavel Zacha, who has scouts talking and a pair of 17-year-old prospects in David Pastrnak and Jacob Vrana. Like Canada, they are expected to be stronger at next year's world juniors in Montreal and Toronto than at this tournament.
Their coach, Miroslav Prerost, told the IIHF website that the team's goal was to reach the quarter-finals.
One Canadian looking forward to the matchup is big winger Frederik Gauthier. Two of his teammates with the Rimouski Oceanic of the Quebec Major Junior Hockey League will be playing for the Czechs — defenceman Jan Kostalek and forward Patrik Zdrahal.
"We didn't bet, but I told them we're going to beat them and they said they would beat us and we joke like that," said Gauthier, a Toronto Maple Leafs first rounder.
Jake Paterson will get a second straight start in goal for Canada. He gave up an early goal he'd probably like to have back against the Germans on Thursday, but then settled down to stop 22 of 24 shots.
Sutter is known to like going with one clear starting goalie, but he doesn't rule out using backup Zach Fucale of the Halifax Mooseheads later in the tournament.
"(Paterson) didn't have a lot of work, but outside of that first goal, he made some key saves for us," said Sutter. "He was there when he needed to be, so he'll get another shot.
"He has to continue to take the ball and run with it. I'm not a believer in rotating goalies in this tournament. You want to go with someone who's riding the hot hand. We went with the 19-year-old to start the tournament, but you still have to assume that at some point, Fucale's going to get that opportunity because we play a lot of games here in a short period of time."
Defenceman Matt Dumba missed practice with an illness on Friday but is expected to be able to play.
"He's just got a little bit of a virus so we're keeping him off the ice," said Sutter. "It's something that started (Thursday) night and he was a little better this morning, so he'll be fine. He was up all night."