The Pats’ defense will have to stop Frank Gore this Sunday.

MCT / DREW PERINE

FOXBORO — The last time they stepped onto the field, the Patriots put forth one of their worst defensive efforts against the run in recent memory, allowing Miami running backs Ronnie Brown (113 yards, 4 TDs) and Ricky Williams (98 yards) to amass a combined 211 rushing yards in a 38-13 Miami victory.

It doesn’t get any easier for the Patriots’ run defense Sunday.

The San Francisco 49ers possess one of the NFL’s most dangerous rushers in Frank Gore.

Gore is the 49ers go-to-guy on offense. He leads the NFL in yards from scrimmage with 525 (369 rushing and 156 receiving). The 5-foot-9, 217-pound bruising back is averaging 92.3 rushing yards per game and 39 receiving yards per game.

“He’s pretty good at everything,” Patriots coach Bill Belichick said. “He really is. He is a complete back. He catches the ball well. He does a good job in pass protection. He’s a strong guy. He’s hard to bring down and he breaks a lot of tackles. He breaks tackles with his quickness but also breaks them with his lower body strength, running through them.

“Guys don’t wrap him up. He puts his shoulder down and runs over them. He has a lot of different tools in the bag. He can do a lot of things — run outside, run inside. He has good patience. He has a good burst. He’s strong, catches the ball well [and] blocks. They are taking him off the field less and less. I can see why. He’s a good player.”

The Patriots hope to put forth a better effort against Gore and the 49ers running game this weekend than they did against the Dolphins. After that atrocious effort, the Patriots now rank 25th out of the 32 NFL teams in run defense, allowing a whopping 140.7 rushing yards per game.

How can they improve their run defense?

“Just be an aggressive, physical defense and get back to the way we normally play,” Patriots defensive back Rodney Harrison said.

“Do your job,” Patriots defensive lineman Vince Wilfork said. “That’s the only thing you can do. Trust your teammates around you, and everything else will take care of itself.”

Last season, the Patriots were 10th against the run, limiting teams to 98.2 rushing yards per game.

After rushing for 130 yards and a touchdown in the 49ers’ 31-13, triumph over the Detroit Lions on Sept. 21, Gore moved into seventh place on the 49ers all-time rushing list. He told the San Francisco media that he was on a mission this season.

“I want to be No. 1, you know?” Gore said. “That would be great.”

Gore hasn’t been too successful when making bold predictions so far in his NFL career, but he plans to change that this year.

A third-round pick in 2005 out of the University of Miami, Gore began his career splitting carries with Kevin Barlow before moving into the spotlight when Barlow missed the final three games of the season in Gore’s rookie year.

The 49ers traded Barlow to the Jets and made Gore their primary back in 2006. It turned out to be a wise decision.

Gore shattered the franchise record in his first season as a full-time starter with 1,695 yards on 312 carries with nine touchdowns. He also had a team-high 61 receptions for 461 yards. He broke the franchise record for single-season 100-yard rushing games (6) with nine touchdowns, which led to a Pro Bowl selection in 2006.

He then boasted that his goal in 2007 was to break Eric Dickerson’s single-season NFL rushing record of 2,105 yards.

It didn’t happen.

Gore fell well short of his lofty goal, recording 1,102 rushing yards and six touchdowns while playing the entire season with a broken right hand. Fully healthy this season, Gore is back on top of his game.

“He’s a good back,” Patriots linebacker Mike Vrabel said. “He’s done a great job…He’s looks good and has had a great season so far. They certainly count on him.”

A breakaway threat who is also a tough inside runner, Gore is not only the team’s leading rusher, but he is also tied with Arnaz Battle for the team lead in receptions.

“He’s a guy that can make all of the different types of runs like a (San Diego running back) LaDainian Tomlinson,” Harrison said. “He stays on the field all three downs. He’s a guy that can definitely hurt you in so many different ways.”

roblee@projo.com