Isaac
Guerendo.
Isaac
Guerendo.
Louisville· 6'0"· 221 lb· 4.33s 40
"A 221-pound back who ran 4.33 with only one full season of college carries on his resume, Guerendo was never a production bet — he was a bet that rare traits would eventually find a lane."Pre-draft read
Rotational one-cut back who spent four years at Wisconsin as a special teams ace and change-of-pace runner before a fifth-year jump at Louisville. Aligns primarily as a single-back on gap and zone concepts, presses the line with long strides and needs only one cut to hit a crease, and his acceleration through the second level turns a five-yard gain into an explosive.
The trait that separates him is a rare size-speed pairing: 221 pounds moving at 4.33 speed, which shows up on perimeter runs and on angles defensive backs misjudge. A converted high school receiver, he tracks the ball naturally on wheel routes and swing screens, and he was a willing pass-protector on third down.
Outside/wide zone with a gap-scheme complement
Year 1: change-of-pace back with 8-10 touches and core special teams snaps. Ceiling: 1B in a two-back committee that hunts explosives on the perimeter.
A grind-it-out inside gap offense that asks him to make the first defender miss in a phone booth on 18 carries a game.
Best used on stretch and split zone where his one cut and long speed can turn a crease into a chunk play.
Isaac Guerendo 2023 Regular Season Highlights | Louisville RB
Full transfer-season reel from his 810-yard, 11-touchdown year at Louisville.
NFL Draft Film Ep 821: Isaac Guerendo / RB / Louisville
Cut-up breakdown of his zone vision, burst and pass-game usage.
49ers fourth-round pick Isaac Guerendo college highlights
Draft-day reel released after San Francisco took him at 129.
Guerendo is a late-blooming athlete whose evaluation was always about projection over resume. He arrived at Wisconsin as a receiver, spent four seasons buried behind Jonathan Taylor and Braelon Allen, and made his name on kick coverage while battling injuries that cost him most of two years.
The Louisville transfer season finally gave him volume, and he answered with 132 carries for 810 yards and 11 touchdowns plus 22 catches, averaging over six yards a pop against ACC defenses in a physical, downhill offense. The tape matched the testing: home-run speed in space, real contact balance and a runner who did not need a designed hole to produce. The flags were as loud as the flashes — 232 career carries, an injury history that limited him to 12 games before age 22, and a runner who occasionally froze on interior reads rather than pressing and cutting.
The board saw a Day 3 developmental back with a special teams floor, and the combine testing pushed him up rooms that value explosion. Taking him at 129 was a bet that a zone-heavy staff could unlock traits college volume never let him show.
- 01
Long speed
His 4.33-second 40-yard dash at 221 pounds demonstrates true home-run range. After clearing the second level, he pulls away from pursuit angles.
- 02
One-cut decisiveness
He presses downhill on zone runs, planting once and getting north without wasted footwork or lateral dancing.
- 03
Contact balance
He runs with a wide base and absorbs glancing hits from defensive backs without losing stride length.
- 04
Receiving background
A converted receiver, he tracks the ball over his shoulder and can be split out for wheels and screens.
- 05
Special teams value
Four years of core kick-coverage work at Wisconsin provide an immediate role on any 53-man roster.
- 01
Limited volume
He accumulated only 232 career carries across five seasons, with projection resting on one productive year of real work.
- 02
Interior vision
He sometimes hesitates on tight inside runs, waiting for a clean lane instead of squeezing through a closing crease.
- 03
Injury history
Hamstring and lower-body issues wiped out most of two Wisconsin seasons, shortening his development runway.
- 04
Age
He turned 24 during his rookie season, providing less projection runway than a typical Day 3 developmental back.
— — — positional median (p50)
- 40 yd
- 4.33sp50
- Vertical
- 41.5inp50
- Broad jump
- 129inp50
- Three-cone
- 6.94sp50
- Shuttle
- 4.15sp50
- Bench
- —rep
| Yr | Team | G | Att | Yds | TD | Rec | RecYds |
|---|---|---|---|---|---|---|---|
| 2019 | Wisconsin | 6 | 1 | 1 | 0 | 1 | 3 |
| 2020 | Wisconsin | 2 | 11 | 36 | 0 | 0 | 0 |
| 2021 | Wisconsin | 4 | 23 | 160 | 1 | 2 | 6 |
| 2022 | Wisconsin | 12 | 65 | 390 | 5 | 17 | 115 |
| 2023 | Louisville | 14 | 132 | 810 | 11 | 22 | 234 |
| Career | — | 38 | 232 | 1397 | 17 | 42 | 358 |
A dash means the figure is not published by a source we trust — never a zero we invented.
Efficient rotational back whose value lives in complementary carries, not volume.
Same long-speed, one-cut profile that grew into a lead role once the runway opened.
Traits-first Shanahan mid-round back who never carved out an offensive role.
Everything above is the pre-draft evaluation. This section is what actually happened — updated year over year.
San Francisco used him exactly how the profile suggested. As a rookie he opened as the third back behind Christian McCaffrey and Jordan Mason, then injuries forced him into December work and he delivered — 84 carries for 420 yards and four touchdowns at 5.0 a pop, plus 15 catches on 16 targets for 152 yards, headlined by a 99-yard game in Seattle. That stretch made him one of seven backs with 80-plus attempts to average five yards per carry.
Then the door shut. He did not win the McCaffrey-backup job in camp, the 49ers traded for Brian Robinson Jr., and Guerendo finished 2025 with zero offensive touches across 14 games and 100 kick-return yards, with healthy scratches down the stretch. A pectoral tear in the 2026 offseason and a third-round pick spent on Kaelon Black pushed him further down the room. In hindsight the pick was fine value for the price; the fit inside a crowded Shanahan backfield was the part nobody solved.