The Green Bay Packers surprisingly re-signed running back Aaron Jones on a four-year contract before he had a chance to hit the free-agent market.According to Adam Schefter, Green Bay Packers are giving Jones a contract worth $48 million, which, on a per-year basis, would average out to $12 million. The agreement also comes with a $13 million signing bonus.Aaron Jones has reached agreement with the Packers on a 4-year deal worth $48 million, including a $13 million signing bonus, @DrewJRosenhaus tells ESPN.— Adam Schefter (@AdamSchefter) March 14, 2021Jones' future with the Packers appeared to be over after the NFL deadline to franchise tag players came and went, a week before the free-agent market opened. The AJ Dillion era was expected to begin.NFL Trade Rumors: What does that mean for second-round pick AJ Dillon?Matt LaFleur believes a great running game is key to a great offense; he favors running backs, and that's a big reason why Dillon isn't a wasted pick.Dillon is capable of starting, but that's not what Green Bay needs from him.Dillon is expected to become the primary backup; he compliments Green Bay's cemented running back. Even though there could be drives or even games, Dillon will get a good amount of carries.There were high expectations for the rookie, and he met some of them. He averaged 5.2 yards per attempt on seven carries in Green Bay's last two games of the 2020 season.Dillon has 97 offensive snaps, 38 of which came from throttling the Titans. The former Boston College running back recorded 124 yards and a pair of touchdowns; he took over as the team's primary back for the evening and played exceptionally well.Over the last few seasons, Jamaal Williams has been Jones' primary backup. Williams accumulated 347 carries, 1,429 rushing yards and six rushing touchdowns.Williams was also a complementary piece, calculating 97 receptions, 699 receiving yards, and six receiving touchdowns.Jamaal Williams barrels ahead for the #GoPackGo score.📺: #CHIvsGB on NBC📱: NFL app // Yahoo Sports app: https://t.co/y4imSy610p pic.twitter.com/HgsedVUjF7— NFL (@NFL) November 30, 2020Unfortunately, Jones's contract marks the end of the Williams era with the Packers. Williams will most likely enter free agency as a solid prospect.Free-agent running back Jamaal Williams acknowledges that he won't return to the #Packers following Aaron Jones' extension: "It's just sad that we won't be able to play together again."— Jason B. Hirschhorn (@by_JBH) March 15, 2021Dillon will be stepping into the role with an exponential number of snaps. The former backup played 481 offensive snaps in the regular season and postseason last season and 402 the year prior.The tandem running backs extend both players' careers by putting less wear and tear on them. An added benefit for the 247-pounder is that the Packers could still potentially start him in the future.Now that Jones and Dillon will defend Green Bay's backfield in 2021, they have the potential to be one of the best one-two punches in the NFL.