If the Vikings don’t re-sign their 2018 starter at three-technique defensive tackle, they could turn to their 2017 starter.

Sheldon Richardson, who started all 16 games last season, is bound for free agency after playing on a one-year, $8 million deal — and Minnesota might not be able to afford bringing him back. Tom Johnson, the 2017 starter who rejoined the Vikings early last season after a short stint with Seattle, also will be a free agent but at a much more affordable price.

“I’ve got interest from (the Vikings to re-sign),” Johnson said in a phone interview. “I definitely would like to return, but you just never know how free agency is going to unfold.”

Johnson, who turns 35 in August, would be willing to accept a one-year contract after free agency gets underway next Wednesday.

“I’m not looking for a multi-year deal,” he said. “I’m in a situation that I’m playing it by ear. … I’m going to see how things unfold.”

Johnson joined the Vikings in 2014 on a one-year minimum deal before signing a three-year, $7 million contract in March 2015. He signed a one-year, $2.1 million deal with Seattle last year before being released after one game, then signed a pro-rated one-year, $1 million contract with the Vikings for the final 14 games.