In what could be an encouraging development for the Washington Redskins, new coach Ron ­Rivera and star left tackle Trent Williams have been in contact, a person with knowledge of the ­situation said Tuesday.

The communication, which could lead to Williams visiting Rivera at the team complex, the person said, might be an important first step toward Rivera convincing the seven-time Pro Bowl selection to rejoin the team. Determining Williams’s future is expected to be a pivotal early step in Washington’s rebuilding process under Rivera, who is evaluating the roster ahead of free agency and April’s draft.

Williams held out for all of last year’s offseason activities and training camp as well as the first half of the season after demanding a trade because he was unhappy with the way the team’s medical staff had handled a growth on his head that turned out to be cancerous. He returned to the club just minutes before the Oct. 29 trade deadline but was placed on the non-football injury list and said the team told him not to come back to the facility.

Rivera has indicated that getting Williams to return is a top priority. One of his first moves was to hire respected trainer Ryan Vermillion, who had been Rivera’s team trainer with the Carolina Panthers. At the time, a person familiar with the move said Vermillion’s hire was made with Williams in mind.

“One of Ron’s top goals is to get Trent back,” the person said. “I know for certain that Ron is going to try to get him back.”

Rivera, who began offseason planning meetings with the Redskins’ coaching and scouting staffs Monday, probably needs to know soon whether a Williams return is possible. If not, the team would need to pursue trade options and either draft Williams’s replacement at left tackle or find one in free agency.

Williams has one year remaining on a five-year, $66 million contract, after which he will be eligible for unrestricted free agency. Washington would save $12.7 million in salary cap space if it trades him, but it would lose a longtime franchise cornerstone who plays a premium position.

NFL Network was the first to report that Rivera and Williams had been in contact.

Williams, 31, became frustrated with the Redskins last winter when he was told that a growth — which he said the team’s medical staff had ignored for years — was actually a rare cancer called Dermatofibrosarcoma Protuberans, or DFSP. Although the cancer has a high survivability rate, he said the cancer was close to penetrating his skull and getting to his brain. He skipped offseason workouts before demanding a trade in the early summer.

A standoff developed between Williams and former team president Bruce Allen, with Williams alleging that Allen refused to trade him out of spite. In a November interview, Williams said he came back to the team intending to play the second half of the season. He added that he was even looking forward to the arrival of a new helmet that was supposed to mitigate discomfort from the still-healing wounds from surgeries to remove the cancer and fix the skin on the top of his head. He said Allen had him placed on the NFI list Nov. 7 in a “vindictive” punishment for not only his holdout but for criticizing Allen and the team’s medical staff in an Oct. 31 interview session with reporters.

“I don’t see how it can be reconciled,” Williams said in November when asked whether his relationship with the team could be fixed. “At the end of the day, I’m a human being. I ain’t like a dog and you can slap the s--- out of me and I’m going to come back the next morning with my tail wagging. This was a conscious decision; they didn’t burn the bridge by accident. This was something they felt comfortable doing, so I got to feel comfortable with moving on, too.”

Allen, who denied Williams’s allegations at the time, was fired the day after the season ended, as was longtime trainer Larry Hess.

Before the cancer diagnosis, Williams and his agent had been talking about a contract extension with the team. And while those talks died during his holdout, some NFL team executives and player agents have speculated that Williams might consider coming back to the Redskins if he can get the security of a new contract.

The market for offensive tackles has increased since Williams signed his contract extension with the Redskins in 2015. Trent Brown signed a four-year, $66 million free agent contract with the Raiders last offseason, and Philadelphia gave Lane Johnson a four-year, $72 million extension in ­November. Williams, who will turn 32 in July, is older than both of those players but could still be seeking a sizable contract.

This year’s draft is considered a strong one for offensive tackles, and there are a handful of starting left tackles set to become free agents, including Indianapolis’s Anthony Castonzo (who has suggested he might retire). Donald Penn played left tackle for the Redskins on a one-year contract last season, but there has been no indication whether Rivera is interested in re-signing him. For now, his focus appears to be on Williams.

More Redskins coverage: