The 49ers have more needs than they can address in one offseason and it’s hard to say which need is their biggest.

The 49ers certainly need to improve their offensive line — Trent Williams is old and everyone else except Dominick Puni is expendable.

They also need to improve their defensive line — Javon Hargrave will be a free agent in March, and Leonard Floyd, Maliek Collins and Yetur Gross-Matos all will be free agents next year.

The 49ers’ run defense has been so bad the past two seasons, they could decide to take a defensive tackle with the 11th pick, but John Lynch and Kyle Shanahan have a miserable track record of drafting defensive tackles in Round 1. So far, they’ve taken Solomon Thomas and Javon Kinlaw — two busts.

The 49ers’ pass rush also has been sub par, particularly this season. That’s because Nick Bosa is the only pass rusher they have who scares anyone. So they could take a pass-rusher, too. And maybe they should.

Whenever the 49ers take a defensive end with a top-15 pick in Round 1, that player is good. Since 1970, the 49ers have taken four defensive ends in the top 15: Nick Bosa (62.5 career sacks and counting), Aldon Smith (52.5 career sacks), Andre Carter (80.5 career sacks) and Cedrick Hardman (122.5 career sacks).

Given the 49ers’ history, maybe they should address their run defense in free agency and draft the best edge rusher available.