That duo was at its best earlier this season against the Phoenix Coyotes, who are winless on the road as they try to hand the Sharks a fourth straight loss Saturday.
San Jose (7-2-1) won its first seven games for the best start in franchise history, but a shootout defeat and two regulation losses have followed. Marleau and Thornton each amassed 14 points through six contests, but both have come up empty over the last four.
"They had a jump on a lot of teams," coach Todd McLellan said. "The power play clicked very well so they got a lot of their points and production in that area. It hasn't been going as well, there's reason for it on both sides of the coin. We've also split them up a little bit to get some other guys going."
San Jose started the season a sizzling 12 for 32 on the power play before going 1 for 21 over its last five games.
"Early on, the power play was going, now it's kinda a little but stale so we're working on that but that'll get us going again," Thornton said.
Marleau and Thornton combined for a season-high seven points in a 5-3 home victory over Phoenix (4-5-2) on Jan. 24. Marleau scored twice in the final 11 minutes as the Sharks rallied from a 3-1 deficit in the third.
That's one of only three road games for the Coyotes, with Dallas the only other NHL city Phoenix has visited this season.
The Coyotes bring an 0-2-1 road record into the opener of a three-game trip and won't have much momentum after losing 6-2 to Chicago on Thursday. Phoenix never recovered after getting outshot 17-4 in falling behind 4-0 after one period.
"This is a good slap in the face right here," coach Dave Tippett said. "We just went out there and we just got kicked. If we don't recognize that, then we've got bigger problems than I think we've got."
Tippett was also unhappy with his team's conduct, criticizing veterans Keith Yandle and Shane Doan for unsportsmanlike penalties. Doan, who is mired in a six-game goal-scoring drought, said he expects the matter to be addressed.
"I hope that's a blip on the radar screen because there's a lot of stuff right there that is not going to be happening on our team," Tippett said. "We'll correct some of those problems."
The Sharks will probably get their first look this season at Mike Smith, scratched with a lower-body injury from last month's meeting. Smith has started Phoenix's last four games, and he's 4-0-1 with three shutouts and a 1.18 goals-against average in his last five versus San Jose.
San Jose did not practice Wednesday after a 5-3 loss to the Blackhawks a day earlier. The Sharks, who returned to the ice both days before this game, embark on a six-game road trip on Monday.
"There's something to be said for getting away," defenseman Dan Boyle said. "I think the day off (Wednesday) was probably welcome and needed."