RENTON — They head into this weekend with a losing record having dropped three of their last four games, and many believe quarterback issues are at the heart of their struggles.

And no, we’re not talking about the Seattle Seahawks, but rather their opponent Sunday, the Dallas Cowboys. After a losing season in 2010, the Cowboys fully expected to rebound and be among the NFC elite this year, but so far it has been an up-and-down season for Dallas, which sits at 3-4 as it prepares to host the 2-5 Seahawks.

The Cowboys are hoping to get right starting this weekend. To do so, they’ll need the good Tony Romo to show up, because, while every team’s fate is determined in part by quarterback play, few teams experience ups and downs at that position more than Dallas.

When Romo’s on his game, he can look like one of the elite quarterbacks in the game. When he’s off, boy can it get ugly in a hurry.

Take, for example, Romo’s performances two weeks apart earlier this season. In a road win against San Francisco — which is much more impressive now than it was at the time — he threw for 345 yards, two touchdowns and no interceptions while playing with a fractured rib and punctured lung. Two weeks later, the Cowboys had a 24-point lead against Detroit, but ended up losing after Romo threw three interceptions, two of which were returned for touchdowns.

“We’ve been kind of up and down and we just need to stack a couple wins together and things will start going the right direction,” Romo said in a conference call. “The only way we can do that is play a good game this week against Seattle.”

Romo has thrown one interception in Dallas’ three wins, and six in their four losses. For Cowboys fans, the experience of watching their team and their quarterback has been referred to as riding the “Romocoaster.”

“They’ve got a good trigger man when he’s hot,” said Seahawks linebacker Leroy Hill. “When he’s hot, they’re tough to beat. When he’s cold, you’ve got a good chance of beating him, so it just depends on which one you get.”

The Seahawks know that Dallas, despite its losing record, is a very dangerous team. The Cowboys have weapons on offense like dynamic receiver Dez Bryant and rookie running back DeMarco Murray, who burst onto the scene two weeks ago with 253 rushing yards in his first start. And Romo is capable of making big things happen.

On defense, few players in the league are having more of an impact than linebacker DeMarcus Ware, who already has 12 sacks this season.

“They have a really difficult team to deal with,” Seahawks coach Pete Carroll said. “… This is a very difficult team to prepare for. It’s a big challenge for us to get right.”

What won’t factor into the Seahawks’ challenge, however, is history. Carroll likes to point out that past results don’t matter, but that is never truer than with this team, which has been almost completely overhauled under Carroll and general manager John Schneider. Yes, it has been two years since the Seahawks were blown out in Dallas, but there are currently just 10 players on the active roster who were on the team in 2009. And if you go back to the previous year when the Seahawks lost big at Dallas, that number drops to six.

“Most of these guys weren’t on that team,” linebacker Leroy Hill said. “So that’s over and in the past.”

And even those few that do remember those lopsided losses aren’t looking back. Following back-to-back losses that have the Seahawks sitting at 2-5, the players have more pressing things on their minds that remember the past.

“That’s definitely not on our minds,” linebacker David Hawthorne said. “We’re just going down there to get back on our feet and get rolling.”

Notable

Quarterback Tarvaris Jackson (pectoral) was limited in practice Thursday a day after practicing fully, but he is confident he will be back in the starting lineup Sunday.

“I feel a lot better,” he said. “I know I’m going to play Sunday now. Last Sunday it was like, ‘I think I’m going to play.’ But there was the chance that, coming in Sunday, my arm might not respond right. But now I’m very sure I’ll probably play Sunday.”

Receiver Sidney Rice (foot), defensive tackle Alan Branch (hip/knee) and tight end Cameron Morrah (toe/knee) were held out of practice, while receiver Mike Williams (hamstring) was limited. Safety Kam Chancellor (knee) and linebacker Leroy Hill (knee) practiced without limitation.

Herald Writer John Boyle: jboyle@heraldnet.com. For more Seahawks coverage, check out the Seahawks blog at heraldnet.com/seahawksblog