Every year the 49ers add a rookie running back and every year Fantasy managers swoon over the pick. It's Guerendo this year, a part-time back from Louisville with good cutting skills and solid size and power to match. He ran a 4.33 in his 40-yard dash, but he's also beginning his NFL career at age 24, making him an older rookie who might not have a long shelf life. If he impresses this preseason then he could end up catapulting to the second string in San Francisco's offense, which would make him a prized pick in the late rounds. Short of that he wouldn't be worth drafting in seasonal leagues but does make the cut as an intriguing second- or third-round choice in rookie-only drafts since he could be McCaffrey's backup as soon as 2025.