Both coaches agree the San Jose center's physical presence is the defining difference in the clubs' first-round playoff series, even though Thornton has no goals and just one assist in three games.
In fact, the Predators have done a fine defensive job against Thornton, checking and hacking and pushing and double-teaming the big forward with a ferocity he rarely faced in the regular season.
But while Nashville is concentrating on San Jose's top line, the Predators haven't been able to keep up with the rest of the Sharks' weapons -- and that's why they're down 2-1 heading into Game 4 on Thursday night.
"People are fearing him now, and that's what you want to see with Joe," Sharks coach Ron Wilson said Wednesday. "He's a man on a mission, and people are picking up on that. ... Even though he's not getting points, he's totally controlling the game.
"When he's on the ice making plays, it's just unbelievable how he competes and is so strong. It's got to be frustrating to play against. He's almost like a beast out there. When he puts his mind to it, you can't take [the puck] from him," he said.
Thornton led the league with 96 assists and 125 points this season, and he spearheaded San Jose's rise from 10th place in the Western Conference to the No. 5 seed in the final 10 days before the postseason. He has been among the prime beneficiaries of the NHL's new emphasis on tight refereeing to allow free movement for its top offensive talents.
"I always got held in the past because I was so big," Thornton said. "Now, with the new rules, they can't hold me. I've never really complained about the refs in my career. I think they've done a great job all year long."
The officiating changes have been a relief to Thornton, who arrived in a trade with Boston on Nov. 30. Though he has set up just one goal against Nashville, he has played the biggest role in San Jose's impressive puck-possession offense that's kept most of the action on the Predators' end of the ice in the series' last eight periods.
Although many teams are content to clog the passing lanes when Thornton holds the puck on the wing or behind the net, the Predators have attacked him with defenders to eliminate any windows for playmaking opportunities.
But Thornton drew four penalties in Game 3, holding onto the puck with his strength and control until the Predators tried something illegal to separate him. Though the Predators agree Thornton has impressive puck-possession skills, they're growing frustrated by their inability to slow him legally.
"I'm starting to look at those penalties, and they're pretty weak," Nashville coach Barry Trotz said after his club's 4-1 loss Tuesday night. "But they are penalties, if you want to go the letter of the law. On some of them, I'm not exactly sure what the rules are. There are different rules for him, I guess."
But this is exactly what Wilson expected in the playoffs. San Jose's coach confidently predicted the officials wouldn't swallow their whistles as they've done in previous postseasons, and it's working out that way for his team.
Entering Wednesday night's games, the Sharks had a playoff-high 25 power plays, scoring on five. San Jose and Nashville are tied with 54 penalty minutes -- but the number is skewed by a 10-minute misconduct against Ville Nieminen of the Sharks in Game 2.
Another example of the Sharks' superior puck possession: They have outshot Nashville 111-72 in the series. If the Predators can't break the cycle -- San Jose's style of controlled puck movement -- they'll be heading home down 3-1 for Game 5 on Sunday.
"They cycle well against anybody," Trotz said. "You look at their top six forwards, they're big men. They can wear you down. It's hard to get it back once they start cycling. It takes a lot of energy to get the puck back sometimes. It takes away a lot of your offense."