49ers RB Jordan Mason sprained his ACL

SANTA CLARA, Calif. – While it remains to be seen whether he will be ready for the Oct. 20 game against the Kansas City Chiefs, San Francisco 49ers running back Jordan Mason received good news Friday about his bruised left shoulder.

Mason suffered a sprained ACL in his shoulder during Thursday night's 36-24 win against the Seattle Seahawks, Niners coach Kyle Shanahan said. Mason will be there every day as San Francisco begins preparing for the Chiefs on Monday.

“We view it as good news,” Shanahan said. “I mean, it’s not guaranteed (next) week or anything. He does have an AC sprain, but I'm sure it wasn't any worse. It will be day by day and hopefully he will be. Good for the game but not a guarantee.”

Mason injured his shoulder with 9:37 left in the second quarter. After a 14-yard run, he landed hard on the shoulder during a tackle by Seahawks safety Julian Love. Mason walked to the sideline and stood there for a while before making his way to the locker room.

Mason was originally listed as questionable to return, but he was back on the field for the first offensive snap of the third quarter. A run to the right gained eight yards, but Shanahan said he could tell something didn't feel right, and Mason went back to the sideline. He did not return to the game despite being available in an emergency.

Rookie Isaac Guerendo and veteran defensive lineman Patrick Taylor Jr. picked up the slack as the Niners rushed for 228 yards on 33 carries.

“I thought they both did a really good job,” Shanahan said. “We didn’t really miss a beat with that. They maintained the overall rhythm of the offense. They hit the right holes, ran hard and made some plays for us, so they were prepared and didn't hesitate when they got their opportunities.”

Mason finished the game with 73 yards on nine carries and caught one pass for 9 yards. His 609 rushing yards this season lead the NFL, while other runners will have to make up for their sixth game this weekend. Mason also scored three rushing touchdowns while filling in for injured star running back Christian McCaffrey (Achilles tendonitis).

“Jordan is as tough as anyone, so I'm sure he'll have the chance to play if he's going to play it,” Shanahan said. “But (we) have to see how the shoulder responds.”

Mason wasn't the 49ers' only notable injury on Thursday. For the second straight game, a kicker was injured in San Francisco while attempting to make a tackle on a kickoff return. Matthew Wright, who just signed with the team on Tuesday, suffered a shoulder injury while attempting to bring down Seahawks returner Dee Williams with 1:17 to play. According to Shanahan, the shoulder “came out a little bit” but then went back in.

An MRI on Wright's shoulder returned a negative result Friday, sources told ESPN's Adam Schefter. He is expected to be able to kick against the Chiefs next week. That means San Francisco probably won't have to use three kickers in three games.

Wright signed with the Niners after kicker Jake Moody suffered a severe right ankle sprain during a tackle against the Cardinals in Week 5. Moody is expected to be out for several weeks. San Francisco brought in several kickers for tryouts last week before signing Wright. In addition to his perfect mark on field goals, he hit all three of his extra points against the Seahawks.