Lynch and Shanahan already had great confidence in the offense's potential, but they knew that it could be something special with McCaffrey in the picture.
"You're not going to make a move like that if you don't think you can compete with anyone in this league, if you don't think this could be the thing to push us over the top," Lynch told NBC Sports Bay Area this week.
Lynch admits that the 49ers loved McCaffrey heading into the 2017 draft. Lynch and Shanahan, in their first offseason with the team, knew they wanted to build a stout defensive line first, though. So they selected defensive lineman Solomon Thomas with the third overall pick. The Panthers added McCaffrey five picks later.
"We studied him a lot, and just his gifts, and always felt it would be a great fit in our offense," Lynch said.
Even as the compensation increased while trying to finalize a deal for McCaffrey, the 49ers felt it would be worth it in the end.
"It was our belief in our team, first and foremost, and then the belief in what Christian could do for us to kind of—I don't want to say unlock because we had been successful, but maybe make us more of a consistent threat to go out and put points on the board each and every week.
"For me, if you don't have Kyle Shanahan and his staff, and the ability to take all those players and come up with game plans that can use all that talent, you don't even think about [the trade]. But I have a tremendous belief in those guys, so ultimately, we pulled the trigger on it."
49ers' surprising O-line
Entering the season, the 49ers offensive line was supposed to be the weak link on a roster that seemed to overflow with talent after nearly every other position. But, this past Monday night, the Arizona Cardinals defense couldn't reach quarterback Jimmy Garoppolo. In the previous game, the Los Angeles Chargers defense got to him just once.
The Niners' offensive line has been a pleasant surprise this season, especially in recent weeks.
"[LG] Aaron Banks is playing better," Lynch said. "We always believed in Aaron, but he's playing better than we could have imagined. [RG] Spencer Burford has done a really nice job."
Lynch believes that Burford has benefited from rotating with Daniel Brunskill. Since returning from a hamstring injury in Week 4, Brunskill has been in on 200 offensive snaps, while Burford has played 283.
"[RT] Mike [McGlinchey] is playing really well, just came off a great game," Lynch continued. "And then [LT] Trent [Williams] is just Trent."
Lynch shared the story of Steve Young, who traveled back to the Bay Area with the team following the game in Mexico City, speaking to the general manager and praising Williams. Young noted that he doesn't think he's seen an offensive lineman play at that level.
"We never take it for granted, but we've got a special player playing that left tackle position, and when guys like Steve Young notice that, I think it's just a testament to what a gifted player he is," Lynch said.