Rams coach Sean McVay says that while he would like to have Aaron Donald in camp, the team is moving forward without him until a contract resolution is reached. (1:14)

The holdout of Los Angeles Rams defensive tackle Aaron Donald might spill into the regular season, a league source told ESPN NFL Insider Adam Schefter on Thursday.

The source said that he could envision Donald sitting out the entire 2017 season, though a lot can change in any negotiation in a hurry. But the fact that such strong speculation exists provides a snapshot that the two sides are not particularly close to a deal.

"Our approach is exactly the same: We're continuing to try to find a solution," Rams coach Sean McVay said after practice Thursday. "He's a very important part of what we want to do. In the meantime, we've got a lot of great guys out here that are working hard and getting ready for this Oakland game and just approaching every single day with the situations that we're throwing at them. Whether that report is true or not, we're continuing to try to find a solution, and we've got some time until that does come."

Donald, who has 28 sacks in his three NFL seasons, is scheduled to make $1,802,250 this season and $6.892 million next year on his fifth-year option.

The 13th overall pick in 2014, Donald has made the Pro Bowl in each of his three seasons and has been named first-team All-Pro after each of the past two years. His 28 sacks from 2014 to 2016 are four more than any defensive tackle in the game.

Last year, Donald led the NFL in quarterback hits and tied for the lead in tackles for loss. Heading into this season, Pro Football Focus deemed Donald the game's best player, regardless of position.

The source told Schefter that the two sides will stay in touch, but there is pessimism about how long the holdout could last.

The team has previously stated its belief that negotiations remain amicable, but the Rams are packing up after three weeks on the UC Irvine campus, and Donald never showed. He also didn't attend the three weeks of organized team activities earlier in the spring, though attendance was voluntary.

The Rams are confident that Donald is staying in shape, but there's no telling when he will show.

"You feel like you're missing something," Rams nose tackle and Donald's good friend Michael Brockers said late last week. "You feel like you're missing a piece of the puzzle. It feels a little weird. But for the most part, we're not really focusing on it. We're not really making it a distraction."

The game's highest-paid defensive player, Denver Broncos outside linebacker Von Miller, signed a six-year, $114.5 million deal that guarantees him $70 million. The highest-paid defensive tackle, Ndamukong Suh of the Miami Dolphins, has a six-year, $114.375 million deal that guarantees him nearly $60 million.

But each of those players had five accrued seasons by the time they signed their deals. The only one among the five highest-paid defensive players to sign his deal after only three seasons was Houston Texans star J.J. Watt, who received a six-year, $100 million deal that guaranteed him nearly $52 million in 2014.

Watt's deal didn't get done until September, however. That timeline is similar to that of wide receiver Tavon Austin and outside linebacker Robert Quinn, who got extended by the Rams heading into their fourth seasons. Neither player held out of camp.

The last player to hold out for the Rams was star running back Steven Jackson in 2008, when the team was in St. Louis.

"We've got to always have contingency plans in place," McVay said of Donald. "But that doesn't change our approach, because we're still trying to find that solution and get Aaron here and be a part of what we're doing. And if not, we need to be ready to adjust."

ESPN's Alden Gonzalez and Dan Graziano contributed to this report.