Jeffery received the franchise tag from the club on Feb. 29. That guarantees the receiver $14.599 million in 2016, unless the two sides can finalize a multi-year agreement before the July 15 deadline.
"They're working at it as we speak," Fox said at the NFL owners meetings in Boca Raton, Florida. "Nobody wants to stay on the franchise tag [because] they [the NFL] make it kind of penalizing to do that. Anybody in the league understands that. But they are constantly working on that.
"Alshon is a guy we wanted back. He's a big target and a big-time player. He actually missed a lot of time for us last year. This will give us another year to figure out where he fits and how well he fits in our system. They're still working at the long-term deal. That is a work in progress, I'm sure, with every franchise-tagged player out there."
A league source confirmed that the Bears and Jeffery's representatives have engaged in multiple rounds of talks. Jeffery is not expected to jump at the first offer presented to him. The former second-round pick out of South Carolina has earned a substantial amount of off-the-field income since he joined the Bears four years ago. Also, with $14.599 million, Jeffery would be one of the NFL's highest paid receivers in 2016.
Jeffery appeared in just nine games last season, due to a variety of health setbacks that began in training camp, when he suffered a serious calf strain in a closed walk-through practice prior to Chicago's preseason opener. Jeffery missed all four exhibition games. In December, his season was shut down because of a hamstring injury.
When healthy, Jeffery is one of the Bears' top players on offense. He caught 54 passes for 807 yards and four touchdowns last season, and he tied a franchise record with three straight 100-yard receiving games against Detroit, Minnesota and San Diego.
Jeffery has a dozen 100-yard receiving games in his four seasons with the Bears, which is tied for fifth in franchise history. He set career highs with 89 catches for 1,421 yards in 2013, and he hauled in 10 touchdowns in 2014.