SANTA CLARA Dre Greenlaw San Francisco 49ers Jersey , Calif. (AP) — passing yards at a record pace, San Francisco 49ers cornerback Richard Sherman criticized the league for rules that he says unfairly favor offenses.The four-time Pro Bowler said defenses are at a severe disadvantage given the rules geared toward protecting quarterbacks.“This is what the league wanted though. They wanted record passing numbers,” Sherman said. “You can’t touch (the quarterback). You can’t tackle him. You can’t hit him high. You can’t hit him low. You can’t knock him down to the ground hard.“You can’t hit a receiver high. You can’t hit him low. You can’t push him, you can barely press him. It’s making it really difficult on teams to combat it because every rule in the book is designed to make sure you don’t get them stopped.”There’s no debating the video game-like numbers being posted. Through the first four weeks, the totals for points scored (3,030), touchdowns (344) and touchdown passes (228) are all the highest in NFL history.The frequency of roughing-the-passer penalties has been criticized.“The roughing (penalty) is the biggest one right now,” Sherman said. “But most of the tackling rules have changed. They’re just trying to make it impossible for guys to play defense.”The league’s goal is to reduce the injuries to the starting quarterbacks. This affected the 49ers as Jimmy Garoppolo will miss the rest of the season after tearing the ACL in his knee against Kansas City on Sept. 23. He was hurt scrambling to the sideline.“My suggestion is to put flags on the quarterbacks,” Sherman said jokingly. “If you don’t want them touched, don’t want them getting knocked down. These D-ends and D-tackles and linebackers have long arms. They’ll be able to snatch these flags off without even having to touch these guys half the time.”Sherman hopes to get back on the field. After sitting out Sunday against the Los Angeles Chargers because of a strained left calf, the veteran practiced in limited fashion Thursday and wouldn’t rule himself out for Sunday’s home game against Arizona.After Sherman was injured in Week 3 against Kansas City, San Francisco coach Kyle Shanahan said the expectation was that Sherman likely would miss “a couple” games.The 49ers have started Jimmie Ward in Sherman’s place, although Greg Mabin rotated in at cornerback with both Ward and Ahkello Witherspoon against the Chargers. Mabin forced a fumble and earned praise from the coaching staff.He showed “great physicality, competitive toughness Steve Young Jersey , communication skills,” defensive coordinator Robert Saleh said. “He did play very well in the game.”Saleh said Mabin would rotate in at cornerback again. If Sherman can go, that will affect things one way or another.NOTES: Left tackle Joe Staley (knee) did not practice Thursday. But two of the 49ers other starting offensive linemen battling knee injuries, center Weston Richburg and right tackle Mike McGlinchey, practiced in limited fashion. Running back Matt Breida (shoulder) and receiver Marquise Goodwin (quadriceps, hamstring) also were limited. … The starting safety tandem of Adrian Colbert (hip) and Jaquiski Tartt (shoulder) participated fully as did running back Alfred Morris (knee). The 49ers landed a running back in free agency for the second straight year when they signed Tevin Coleman this week.Coleman’s arrival has led some to wonder about what the outlook is for last year’s signing. Jerick McKinnon tore his ACL before the start of the season and has no guaranteed money left on his deal, so it’s hardly out of left field to think the team might part ways with him while moving forward with Coleman, Matt Breida and Raheem Mostert.On Thursday, 49ers head coach Kyle Shanahan said that’s not the plan. He said the depth at the position is not a problem and didn’t rule out having all four running backs — Mostert is a core special teamer — active for games. McKinnon still has rehab work to do as well and Coleman’s presence allows that to continue without worries about an exact date that he’ll be ready.That outlook could change as other roster needs and/or offers from other teams pop up this offseason, but, for now, the Niners say that four is not a crowd.