SANTA CLARA,Calif. -- While the San Francisco 49ers contemplate reducing NaVorro Bowman’s work load, specifically on obvious passing downs, defensive coordinator Eric Mangini said the inside linebacker’s coverage woes are not his problem alone.

“It’s like all of our pass coverage,” Mangini said Thursday. “There’s been times where it’s been really good and outstanding, and then there’s been times where it hasn’t been what we wanted.

NaVorro Bowman's 44 tackles rank sixth in the NFL. AP Photo/Tony Avelar

“And all that stuff works together. It’s how long do you have to cover for? How quickly is the rush getting there? Is the rush affecting the quarterback? Are we able to bat any balls? All that stuff ties in because the amount of time you have to cover, there’s a set route and then there’s a route that happens after things break down, which makes it harder.”

Bowman is returning from a devastating left knee injury suffered in the NFC title game on Jan. 19, 2014 that forced him to miss all of last season.

So while his straight-ahead pursuit seems unaffected, his lateral movement appears compromised. He has a minus-5 grade in coverage, per Pro Football Focus, and has surrendered 21 completions in 22 targets for 202 yards and two touchdowns.

Bowman’s 44 tackles rank sixth in the NFL and he has played 331 of the Niners’ 343 defensive snaps thus far. So the obvious question is this: Is he wearing down through five games?

“No,” Mangini said. “And I think [49ers coach] Jim [Tomsula] has done a good job of trying to give him some time [off] and NaVorro is great about communicating where he’s at, whether it’s with me or with the trainers or with Jim. And, we’re all working together. What he’s come back from is not an easy thing at all and he’s done a great job when you put it in perspective of what he went through and how hard he had to work to get back there. What he doesn’t want and we don’t want, nobody wants is [to] take any steps back with that.

“So, we’re trying to be as conscientious and as open collectively about it to get him in the best spot to play on Sundays.”

Tomsula has given Bowman Wednesdays off in an effort to keep him fresh.