[3] Idzik was also invited to play for the South squad in the third annual Mahi Shrine North-South College All-Star Football Classic, a charity game held on Christmas night at Orange Bowl Stadium in Miami.

[4] The 1951 yearbook, The Terrapin, described Idzik as a "backfield bulwark who was demon on defense—Could have starred on offense but was defensive necessity.

[7][8] Having played college football under Jim Tatum, Idzik was the split-T expert on the Tennessee staff.

[13] As head coach, Detroit failed to achieve a winning season and Idzik amassed a record of 6–21–1.

[18] Idzik was considered a candidate for the Tulane head coach post after Tommy O'Boyle resigned, but the job ultimately went to Jim Pittman.

[18] Idzik then moved on to the National Football League, where he joined the staff of the Miami Dolphins as its backfield coach.

"[20] In 1967, Idzik was a frontrunner for the vacant head coaching job at his alma mater, which went instead to fellow alumnus Bob Ward.

[28] In 1978, Idzik expressed an interest in the vacant head coaching position with the New York Giants,[29] but he did not receive the job.

The Associated Press reported that he did not get along with head coach Walt Michaels, and that he favored embattled quarterback Richard Todd over back-up Matt Robinson.

[2] His son, John Idzik, Jr., has held front office positions in the NFL with the Tampa Bay Buccaneers, Arizona Cardinals and Seattle Seahawks,[34] and also was the general manager of the New York Jets.

Idzik died at his home in Chadds Ford Township, Delaware County, Pennsylvania on December 7, 2013.