Forty-Niner fans expect to hear general manager John Lynch come out some time next week and say those magic words, “We went in aggressively.”



Only the name in reference wouldn’t be Khalil Mack but Le’Veon Bell.

Lynch likes to go in aggressively when it comes to roster assembly. But having failed to get Mack -- probably because even Jon Gruden wouldn't have been crazy enough to move his best player to the team the fan base hates more than any other -- Lynch also has tempered expectations on the next-level pass rusher.



“(W)e also talked about, ‘Don’t try to solve every issue this year,’ ” Lynch said Thursday. “It’s on my desk right here: 'Sustainable Success.’ ”



That sentence is sort of a hint as to why Bell might not be on Lynch’s mind quite as much as Mack was.

The 49ers enter a new season relatively bereft of running backs because of Jerick McKinnon’s season-ending ACL tear, and in the superficial world of “well, just go get another one,” Bell’s name would leap out. He's still at the top of his game physically, his position in Pittsburgh is precarious because of his protracted holdout, and he would come to a San Francisco team that wouldn’t feel the need to showcase him 25-plus times per game.



But Bell’s name doesn’t come up -- or at least it hasn’t. The problem of his franchise tag, which would have to be played out, is one thing. The cost of acquiring him (high draft picks) is a luxury the 49ers seem reluctant to spend, and there is no guarantee that Bell would want to stay anyway, nor that the miles already on him would make him as appealing.



In short, the 49ers’ putative interest in him and “sustainable success” seem to be an ill fit.



Bell is the kind of player you chase if you believe you’re a running back away from winning right now, and damn the future. Unlike Mack, he very well could be a rental. It isn’t that he can’t fill the McKinnon hole, it’s for how long. That unknown would seem to give Lynch pause.



Plus going all-in on Bell almost certainly would mean exhausting much of the 49ers' remaining salary cap space and draft capital without helping the defense that's already believed to be the team’s prominent weakness. You can almost hear Lynch rubbing his forehead in exasperation.



Ultimately, the 49ers probably will be fine with not being aggressive enough on Le’Veon Bell . . . that is, unless/until Alfred Morris goes down, too -- and that’s not out of the realm of likelihood because football.



So until success arrives in Santa Clara, John Lynch is going to be picky about sustainability. It's simply the nature of the beast he's riding today.

This Sunday, be sure to watch 49ers Pregame Live at 9 a.m. and 49ers Postgame Live immediately after the game on NBC Sports Bay Area and live streaming on the NBC Sports app. Greg Papa, Donte Whitner, Jeff Garcia, Matt Maiocco and Laura Britt will have everything you need to know from the 49ers’ season opener.