The trend is gaining steam.
Johnson (6-2, 200) has all the physical tools, but is considered a developmental project. In school he played safety and also has experience covering the slot.
The Pennington, New Jersey native turned down a scholarship offer from Jim Harbaugh at Stanford, much like another recent 49ers draft pick, Eric Reid.
"I feel like a lot of teams were looking at me to be a press corner due to my length and my speed - which was proven at the combine by running the good time that I did," Johnson said.
Johnson ran a 4.45 40 at the combine and jumped 38.5 inches in the vertical - two very good numbers for a player his size. But in his case, his measurables outweigh his production on film. Johnson is still viewed as a project, although he has plenty of upside.
San Francisco took Johnson two slots after the Cleveland Browns selected Lindenwood's Pierre Desir, another corner with good size commonly linked to the 49ers during the evaluation process.
"They want me to come in and just compete. Bring in a great work ethic, just be out there to compete, compete at corner," said Johnson.
"It's going to be great."
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