Editor's note: The free-agent signing period begins Wednesday at 1 p.m. This is Part Three of a series that examines the 49ers’ biggest offseason needs and their options in free agency. Previously, we focused on wide receivers and linebackers.

The 49ers entered the offseason one year ago feeling good about Jaquiski Tartt and Adrian Colbert as their starting safeties.

This year, nobody’s starting job is secure after both players struggled with injuries and consistency.

The 49ers received some encouraging production from rookie Marcell Harris, who started the final five games at strong safety. He placed himself into position to compete for a starting job.

The team would like to re-sign versatile defensive back Jimmie Ward. But his own history of injuries is the reason the 49ers are reluctant to offer him a multiyear contract extension.

For a team that recorded an all-time NFL worst two interceptions over the course of 16 games, the 49ers need some playmaking ability in their defensive backfield as they enter the free agent market.

On the roster

Jaquiski Tartt, Adrian Colbert, Marcell Harris, D.J. Reed, Tyvis Powell, Terrell Williams, Godwin Igwebuike, Tyree Robinson

On the market

The safety market is deep and talented, with longtime Seattle Seahawks star Earl Thomas the headliner. Thomas is to this defense at safety what Richard Sherman is at cornerback. The 49ers’ scheme is based on the Seahawks' defense, and nobody was better in the role of the “eraser” at free safety than Thomas.

 

Thomas, who turns 30 in May, missed 19 games over the past three seasons because of injuries. He sustained a broken left leg in the fourth game last season. Still, Thomas figures to garner a lot of attention on the open market. He has 28 interceptions in nine seasons, including three in just four games last year.

Thomas is not alone. Among the others who figure to be attractive targets on the open market are Landon Collins (New York Giants), Adrian Amos (Chicago), Tyrann Mathieu (Houston), Lamarcus Joyner (L.A. Rams), Ha-Ha Clinton Dix (Green Bay) and Tre Boston (Arizona).

Offseason approach

The safety market was slow last offseason, and teams appear less and less enthused about paying top dollar for the position. That could work to the 49ers’ advantage.

The 49ers have approximately $70 million in salary-cap room. They would like to add a player to replace Colbert in the starting lineup -- not so much because they are disappointed in him but because that means they would have upgraded the starting defense as well as the depth.

The 49ers figure to get involved with Thomas. But he is a Texas native, and the Dallas Cowboys tried to acquire him in a trade last offseason. Former Seahawks defensive coordinator Kris Richard is the Cowboys' new defensive backs coach. Robert Saleh, the 49ers’ defensive coordinator, worked with Thomas during his time in Seattle, so he knows what kind of value he brings to a defense.