The 49ers need to draft a linebacker to replace Dre Greenlaw — that’s obvious. But how early will they draft one?

Technically, the 49ers could justify using their first-round pick to draft a linebacker — that’s how important Greenlaw was to the team. They currently own the 11th pick, and the last time they drafted a linebacker with pick No. 11, they got Patrick Willis.

But there may not be another Patrick Willis in this year’s draft. He’s a Hall of Famer, a one-of-one. And the last time the 49ers drafted a linebacker in Round 1, they took Reuben Foster, one of the biggest busts in franchise history.

Meanwhile, Greenlaw was a fifth-round pick, and Fred Warner was a third-round pick. The 49ers picked these players after whiffing on Foster, so it appears they learned their lesson when it comes to drafting linebackers.

Robert Saleh, the 49ers current defensive coordinator, was a linebackers coach for years and may have the best eye in the league for drafting the position. If he thinks he can find another Greenlaw in Round 5, he’ll wait and take defensive linemen early in the draft.

Because the 49ers currently need three new starters on the defensive line. This offseason, they released Javon Hargrave, Maliek Collins and Leonard Floyd and signed no one to replace them. Which means their current starters are Nick Bosa, Jordan Elliott, Evan Anderson and Yetur Gross-Matos.

Since John Lynch and Kyle Shanahan joined the 49ers in 2017, they have drafted just one excellent defensive lineman — Nick Bosa. They do not have a great eye for drafting this position. They need to draft some blue-chippers.