Chicago Cardinals Upon his retirement during the
1937 NFL season, Handler was named a full-time assistant coach. His career with the Cardinals appeared to have ended on November 28, 1938, when he and head coach
Milan Creighton resigned following a 2–9 finish, however Handler later reconsidered his decision and continued as an assistant coach. On July 3, 1943, Handler took over the Cardinals' head coaching duties when head coach
Jimmy Conzelman accepted a front office position with baseball's
St. Louis Browns. However, with manning shortages due to World War II, the Cardinals lost all 10 games that season. The team then merged with the
Pittsburgh Steelers in 1944 to form what was referred to as "
Card-Pitt" in the standings. Handler and
Walt Kiesling were named the team's co-coaches. That effort also resulted in a winless season in 1944, and after a 1–9 season the next year, Handler gave way for the returning Conzelman. The return of Conzelman and many of their top players, helped the Cardinals improve to 6–5 in 1946, followed by the franchise's only undisputed NFL title the next season, with a 28–21 victory over the
Philadelphia Eagles on December 28, 1947, at
Comiskey Park in Chicago. That season Handler was an assistant coach on the Cardinals' NFL Championship team. In 1949 Conzelman again resigned as head coach of the Cardinals. As a result, Handler and fellow assistant
Buddy Parker were named as co-head coaches for the team in a unique arrangement on February 3, 1949. The decision was brought about by the two owners' different coaching preferences. The decision was blamed for the Cardinals 2–4 start that season. However Parker soon took over as sole coach when Handler shifted to a front office role later that season. When Parker left after the season,
Curly Lambeau, the legendary coach and founder of the
Green Bay Packers, was hired as his replacement. Upon taking over the coaching position, Lambeau brought back Handler as the team's offensive line coach. However, the new staff continued to struggle, and after a 7–15 mark, Lambeau resigned as the team's coach on December 7, 1951. Handler and
Cecil Isbell were then left to coach the team's last two games. Handler's 0.105 winning percentage is the lowest in NFL history for coaches with at least five seasons.
Chicago Bears After more than two decades with the same team, Handler moved to the north side of Chicago to become the offensive line coach for the Chicago Bears on July 19, 1952. There he soon became a top assistant under coach
George Halas. In addition to his coaching duties, Handler also served as a scout for the team for the next 16 seasons. In 1956 Handler helped the team reach the NFL Championship game. He then helped the squad capture the NFL title seven years later, in a storied 14–10 Bears victory over the
New York Giants, on a frigid day at
Wrigley Field in late 1963. ==Death and legacy==