San Francisco 49ers rookie linebacker Reuben Foster missed six of the team's first eight games to start the season. Since then, he has played in all six of the 49ers' next games. Foster has played so well that he was named the Defensive Rookie of the Month for November.

Foster will occasionally leave a game with an injury, but it's never enough to keep him out. The same thing happened a couple of times on Sunday during the 49ers' 25-23 home victory against the Tennessee Titans. Foster appeared to injure his hand at the start of the second quarter and then was slow to get up off the field late in the fourth quarter after helping cornerback Dontae Johnson tackle Titans wide receiver Eric Decker. The latter incident was enough to send Foster into the blue medical tent for further examination. He was back on defense two plays later.

Following the play where he seemingly got hurt, Foster laid on the field for a few minutes while being examined by 49ers personnel. One person who was not out there was head coach Kyle Shanahan.

On Monday, Shanahan was asked about Foster's trend of brief game exits.

"I think everyone can see Reuben throws his body around," Shanahan said. "He plays very hard. That's something you have to ask Reuben about. He's already tricked me enough. I told him, 'I'm not coming out there anymore.' And then one day I'm going to need to. Hopefully not.

"I think it was pretty serious and he's back out there a couple of plays later. But I know he plays through a lot of pain. He throws his body around. You guys can see how violent he plays. But he definitely has made me nervous many a times, so I try not to worry too much until he's out longer than a couple of plays."

Foster ended the game credited with seven tackles and an assist against the Titans. The 49ers defense held the Titans to just 90 yards rushing. It was the fourth consecutive game a 49ers opponent has failed to reach the 100-yard rushing mark.