RENTON, Wash. — The defining moment of Seattle’s 14-9 win at St. Louis on Oct. 28 came when Seahawk receiver Golden Tate leaped to catch a deep pass from Russell Wilson, then taunted Rams defensive backs by waving as he raced into the end zone to complete an 80-yard touchdown play.

Tate was assessed a penalty for unsportsmanlike conduct, fined $7,875, and later said he was sorry.

As the two teams prepare for a rematch Sunday at 1:25 p.m. at CenturyLink Field, though, Tate promises a similar penalty won’t happen again.

He won’t promise, though, to stay away from engaging in a few verbal battles with the Rams. The trash talk, in fact, may already be starting.

Seattle players say the rivalry with the Rams has become as heated as any they have, especially since Jeff Fisher took over as coach before the 2012 season.

“Yeah, they talk a lot more trash,” said fullback Michael Robinson when asked if anything has changed with the Rams since Fisher took over. “I don’t know why.”

Robinson then smiled and noted that Fisher is “is part of the (NFL) Competition Committee, too, so you would think they would be more on the rules. But they do a lot more chirping.”

Tate agreed.

“Really since I’ve been there, they have been a chirpy group,” Tate said. “I think at times we can be a chirpy group, also. I don’t think there is anything wrong with it. I think we both have a lot of respect for each other. When you are playing this game, it’s tough not to start talking a little bit. It’s just part of having emotion in a game like this.”

And Sunday’s game promises to be as intense as any the Seahawks will play this season due to the suddenly heightened stakes.

The Seahawks blew a chance to win the NFC West and take the home-field advantage throughout the NFC playoffs when they lost to Arizona, 17-10.

They then watched Monday as the 49ers kept alive their quest to win the NFC West by holding on to beat the Atlanta Falcons, 34-24.

Safety Earl Thomas and a group of other Seattle defensive backs were watching together as NaVorro Bowman clinched the win for the 49ers with a highlight-reel 89-yard interception return.

“Obviously it didn’t happen the way we wanted it to,” Thomas said. “But at the end of the day, it’s in our control, and what better can you ask for? We can do it ourselves — we don’t have to depend on anybody.”

The Seahawks have a simple playoff formula Sunday: Win and they are the NFC West champs and the No. 1 seed in the NFC. Lose and then they are at the mercy of the 49ers, who will play at Arizona at the same time.

San Francisco, by virtue of a better divisional record, would win the tiebreaker if the 49ers and Seahawks each finish 12-4. That would relegate Seattle to the No. 5 seed and having to play a road game the first weekend.

Seattle’s focus this week, though, is on beating the Rams, something the Seahawks haven’t found easy the past two years, despite winning two of three in that time.

Seattle split a pair of close games with St. Louis in 2012 (losing 19-13 in St. Louis and winning 20-13 in Seattle) and then beat the Rams in October in a contest in which they were outgained 339-135 yards and had to stop a play at the 1-yard-line as time ran out.

As is the case with all divisional games, Robinson says the preparation for this game is relatively simple due to familiarity. That doesn’t mean it will be easy.

“We’ve got it cut out for us this week,” he said. “We’ve got to go in and execute. It’s all about execution. We know what they are going to do and they know what we are doing to do. Nothing is going to change. We’ve just got to go out and out-compete them. There’s no puzzle. Just got to go play and execute.”

And try to rein in the emotions, tough as that may be at times.

“If I score, I won’t be waving bye to them as I am running by them,” Tate said. “I will just score the touchdown and get back in the huddle and try to score another one. So I’m going to stay away from penalties.”

Still, he added, a little chatter is inevitable.

“You know, I’m a talker,” Tate said. “We are men here competing on the football field. They are already trying to give concussions and tear ACLs. I mean, there is going to be a little chatter. I’m just going to keep it within the rules.”