Los Angeles Rams chief operating officer and vice president Kevin Demoff said on Tuesday the team is “working on” an extension for defensive tackle Aaron Donald and hopes to have a deal done before training camp opens in late July.”Well, [the extension] will be done before the stadium’s done,” Demoff joked to NFL Network’s Steve Wyche on Tuesday from a ceremony at the team’s stadium construction site in Inglewood, Calif. “Nah, we’re going to keep wishing and hoping.”I hope it’s done sooner than training camp, but if it goes to training camp, our goal is to make sure it’s done and that he feels rewarded and that it’s a win-win deal for both sides.”Donald, 27, missed the entirety of the Rams’ offseason workouts and practices as he seeks an extension entering the fifth-year option of his rookie contract. The reigning Defensive Player of the Year, Donald is set to make about $6.9 million in 2018. Von Miller is the NFL’s highest-paid defensive player at about $19 million annually.Donald held out of training camp last season while seeking an extension but showed up in time for Week 1. The coaches held him out until Week 2 as a precaution, rather than having him play so soon after returning.Demoff was clear that the team intends to keep No. 99 in a Rams uniform for a long time, especially with their stadium — which will be shared with the Los Angeles Chargers — set to open in 2020.