Less than three weeks after the Jets gave General Manager Mike Maccagnan responsibility to oversee their all-important draft selections, they fired him, a stunning move by a team already noted for a long history of mismanagement.The dismissal on Wednesday brought to an abrupt halt the slow buildup of credibility the Jets had enjoyed over the last few months, and also placed Adam Gase, the team\u2019s new head coach, in the spotlight for whatever role he may have played in an apparent power struggle.Jets chief executive Christopher Johnson issued a statement announcing that Maccagnan had been fired and that Gase would take over his duties on an interim basis while Johnson searches for a replacement for Maccagnan. Johnson noted that Maccagnan was crucial to implementing critical decisions over the past few months that will undoubtedly affect the team for years to come.\u201cThis morning, I informed Mike that he was being relieved of his duties as general manager of the team, effective immediately,\u201d Johnson said in a statement. \u201cMike helped to execute the strategic vision of the organization during the last four seasons and especially the past few months. However, I came to the decision to make a change after much thought and a careful assessment of what would be in the best long-term interests of the New York Jets.\u201dJohnson, who took over management of the team from his brother, Woody Johnson, now the U.S. ambassador to the United Kingdom, gave no specific reasons for firing Maccagnan, who had replaced John Idzik in January 2015.Replacing a general manager so soon after the draft, in any sport, is often interpreted as a sign of organizational bungling and disarray. Why not make the change earlier to allow the replacement time to set the philosophy and direction of the team, much as the Jets did by firing Coach Todd Bowles immediately after the season and then hiring Gase?Maccagnan was instrumental in choosing Gase, who had been fired by the Dolphins in December after compiling a 23-25 record in three years in Miami.Maccagnan also oversaw the team\u2019s aggressive approach in free agency, spending more than $100 million on players, including the star running back Le\u2019Veon Bell and linebacker C.J. Mosley.But there had been reports during last month\u2019s draft that Maccagnan\u2019s job was in jeopardy and that he and Gase were at odds over which free agents to sign and for how much, reports the Jets quickly dismissed.Maccagnan said he would not address reports of friction between him and Gase and added that he liked working with the new coach.\u201cHe\u2019s been in tune, pretty much in step with all the things we do,\u201d Maccagnan said.Last week, Gase continued to rebut the reports, saying he was angered by them.He told reporters that there were merely some healthy disagreements over players. \u201cIf everybody just agreed on everything, it would be boring,\u201d he said. \u201cYou need to have a little excitement every once in a while.\u201dMuch of the excitement for the Jets over the past five decades has come off the field, rather than on it, with only sporadic periods of success.In his last three years with the team, the Jets had a record of 14-34 and finished in last place in the A.F.C. East each year. The team showed some progress after the recent draft selections of Leonard Williams, Jamal Adams and particularly Sam Darnold, who displayed enough promise in his rookie season last year to be considered the Jets\u2019 quarterback of the future.Maccagnan had paid handsomely, with a first-rounder and three second-rounders, to move up in the 2018 draft to select Darnold, a Southern California star, at No. 3.That move seemed to make up for drafting quarterback Christian Hackenberg in the second round of the 2016 draft, a move widely considered to have been a bust. This year, the Jets earned praise for their selection of Quinnen Williams, the Alabama defensive tackle, with the third overall pick.