Cook suffered a torn ACL in Week 4 a year ago, bringing a premature end to his rookie season. He had only two carries for one yard in the preseason, prompting questions of how he will be used against the 49ers.
"We're not sure yet. We're going to see how it goes," Vikings offensive coordinator John DeFilippo told ESPN on Thursday. "There's nothing that hasn't told us that he can't carry the load. If there's something that during the game ... if that does arise where he needs a break, we're confident in all the guys that we're able to put in the football game."
Cook told the St. Paul Pioneer-Press that his knee is "fine" but acknowledged he was unsure how he would hold up under a heavy workload.
"Well, we're going to find out real soon," Cook said. "It's different, man. In practice, I'm trying to help myself by finishing runs and finishing plays to get myself in that type of shape. Once the game comes around, it's a different story. It'll be a mental thing on the other side with pushing through and wanting to get it done."
A second-round draft pick out of Florida State in the 2017 NFL Draft, Cook burst onto the scene by rushing for 127 yards on 22 carries in his professional debut.
Cook amassed 354 yards rushing on 74 attempts, averaging a robust 4.8 yards per carry, before suffering a torn ACL in Week 4 against the Detroit Lions last season.
The 5-foot-10, 210-pounder scored a rushing touchdown in each of his final two games before he was hurt. He also had 11 receptions for 90 yards.