The 49ers’ list of needs will change pretty dramatically between the opening of free agency in mid-March and the NFL draft in late April. Their ample salary cap space could make them players for multiple top-end free agents. The draft also offers several opportunities to add the talent necessary to fill out the biggest holes on their roster.
Instead of trying to predict which roster weaknesses they’ll strengthen where – we found a draft prospect and free agent to fill each of the 49ers’ biggest needs:
Edge rusher

Draft pick – Nick Bosa, Ohio State
Bosa is the top edge rusher in the 2019 draft class. He posted 17.5 sacks and 29 tackles for loss in 29 games for the Buckeyes. A core muscle injury cut his final season down to just three games, but he showed at the combine there won’t be any lingering effects from surgery on that core muscle. He wasn’t the most athletic edge player at the combine, but he tested well enough to match his tape and cement himself at the top of the class.
Free agent – Justin Houston
The Chiefs are set to release the 30-year-old in an effort to find some cap relief, and the 49ers should take advantage of an available pass rusher he tallied 9.0 sacks in 12 games last season. He’s still a wrecking ball despite turning 30 in January, and the 49ers could use him in a more rotational role that should maximize his effectiveness. Houston will command a good-sized contract on the open market, but he won’t be as expensive as some of the other top edge rushers.
Wide receiver
Draft pick – Deebo Samuel, South Carolina State
It doesn’t appear the 49ers are prioritizing a top-end wide receiver, which means they can wait until Day 2 to find one. It’s hard to envision the 49ers passing on Samuel if he makes it to the No. 36 pick, and a trade up from there to grab him isn’t out of the question. He’s not an elite athlete, but he’s great with the ball in his hands and his route running allow him to frequently get open. Samuel could step in and replace Pierre Garçon on Day 1.

Free agent – Tyrell Williams
Williams doesn’t fit the typical mold of a Shanahan wide receiver, but he’s a big target who can do more than just run in a straight line. His 6-4, 205-pound frame would make him San Francisco’s biggest receiver, and give them unique size that would help in the red zone. Williams has shown the ability to be effective in other areas of the field though, which could be enough to earn him a look from the 49ers.
Safety

Draft pick – Sheldrick Redwine, Miami
San Francisco likely won’t aim to fill their safety need until later on Day 2, and possibly early Day 3. That makes Redwine an extremely intriguing prospect for the 49ers. He had a terrific combine and plays with a tenacity that fits the profile of a strong safety in San Francisco. However, he’s versatile enough that he could play free safety if he needs to move there. Additionally, his name is elite. That counts for something here.
Free agent – Earl Thomas
There’s a very real scenario where the 49ers draft Redwine and sign Thomas. It appears the only real contenders for the former Seahawks safety are the 49ers and the Dallas Cowboys. San Francisco’s cap situation is more favorable than Dallas’, which should allow them to make a better offer. Thomas is the best player in the league at the single-high safety spot, and the 49ers should do whatever it takes to plug him into their starting lineup.
Linebacker
Draft pick – Mack Wilson, Alabama
A scenario where Wilson falls to No. 36 could put the 49ers in a tough spot. He has all the physical tools to be a dynamite WILL linebacker next to Fred Warner. He’s 6-1, 240 pounds with a ton of range that jumps off the screen when watching him. His ability to cover might make him enough of a commodity that he goes in the first round. If he drops all the way to No. 36 though, and the 49ers haven’t filled this need in free agency, Wilson would be tough to pass up.

Free agent – CJ Mosley
Signing Mosley shoves linebacker way down the 49ers’ list of draft needs. Mosley is just 26-years old with four Pro Bowls already under his belt. His combination of football IQ, size and athleticism make him an ideal fit in any defense. He’ll command big money on the open market, but he and Warner would be a foundational duo in the heart of the 49ers’ front seven.
Cornerback

Draft pick – Lonnie Johnson, Kentucky
There aren’t many cornerbacks in this draft who look the part of a 49ers cornerback more than Johnson. He measured out at 6-2, 213 pounds with longer than 32-inch arms. His athleticism and productivity in two years with the Wildcats aren’t Earth-shattering, which could cause him to slide down the draft. Snagging Johnson early in Day 3 would land the 49ers a potential starter without investing significant capital in the position.
Free agent – Pierre Desir
Desir checks all the physical boxes for San Francisco. He’s 6-1, 198 pounds with 33-inch arms. The 28-year-old finally put together a strong, full season with the Colts in his fifth NFL season last year. He started 12 of 16 games after having just 13 starts his previous four seasons. A lack of top-end athleticism has hurt Desir throughout his career, but San Francisco can put him in a position to thrive without those elite athletic traits. Finding a veteran who can slide into the mix as a starter could be valuable for bolstering the depth in the 49ers’ secondary.