49ers shopping list

A look at the 49ers’ top three positions of need entering free agency and logical targets to fill each need:

PASS RUSHER

Alex Okafor: Players with sack potential who reach the open market generally have at least one obvious wart. In Okafor’s case, he sustained a torn Achilles in November after collecting 4.5 sacks in 10 games for New Orleans.

Trent Murphy: The former Stanford All-American had a career-best nine sacks for Washington in 2016, but missed last year with a torn ACL sustained in August.

WIDE RECEIVER

Allen Robinson: He sustained a torn ACL in the Jaguars’ 2017 season opener, but his NFL resume — highlighted by his 80-catch, 1,400-yard, 14-TD season in 2015 — makes him the top WR prize.

Sammy Watkins: A notch below Robinson, Watkins, the fourth overall pick in 2014, has yet to fully realize expectations. He had 39 catches, 593 yards and eight TDs after he was traded by the Bills to the Rams in August.

CORNERBACK

Rashaan Melvin: This match was more logical before the 49ers landed Richard Sherman. Higher-end CBs such as the Colts’ Melvin presumably will be attracted to teams with obvious starting openings.

Aaron Colvin: A versatile part-time starter who has played slot in his four-year career with Jacksonville, Colvin could serve as a No. 3 cornerback behind Sherman and Ahkello Witherspoon, the presumptive starters.