Imlach second stint with the Leafs was very contentious. He implemented a dress code which required that all players wear a jacket and tie when in the Leafs' offices. Tiger Williams was fined $250 for not wearing a tie, and the fine would have doubled for a second offence. Players were no longer allowed to drink beer on plane and bus rides back from road games.
Imlach quickly butted heads with Leafs captain Darryl Sittler, using confrontational tactics to try to undermine his influence on the team. Imlach also disliked Sittler's prominent role in the NHL Players Association; during Imlach's first stint with the Leafs, he was well known as an ardent foe of the union and its executive director, Alan Eagleson.
In September, Imlach went to court in an unsuccessful attempt to get an injunction to stop Sittler and teammate Mike Palmateer from appearing on the TV show Showdown. Sittler had a no-trade clause in his contract and, through his agent, had insisted on $500,000 to waive it. With Sittler apparently untouchable, Imlach traded Sittler's best friend Lanny McDonald (#6 on my list of worst Leafs trades) to the pathetic Colorado Rockies on December 29, 1979 for Pat Hickey and Wilf Paiement. In response, Sittler ripped the captain's C off his sweater, later commenting that a captain had to be the go-between with players and management, and he no longer had any communication with management. An anonymous player told the Toronto Star that Ballard and Imlach made the trade specifically to undermine Sittler's influence on the team. Tiger Williams was traded to the Canucks for Bill Derlago and Rick Vaive. Pat Boutette was shipped off th Harford and Mike Palmateer was sent to Washington.
Imlach also reached into the past signing one time nemesis 39-year old Carl Brewer in a move that infuriated the players and raised eyebrows around the league. Brewer returned to the Maple Leafs on December 26, 1979. Many players on the Leafs felt that Brewer was a spy for Imlach. In Brewer's first game, many of his teammates were openly hostile to him. Brewer's defense partner was Borje Salming, and Salming refused to pass Brewer the puck.
In March 1980, after Floyd Smith was injured in a car accident and acting coach Dick Duff led the team to two lopsided defeats, Imlach named himself as coach. Imlach was able to get the Leafs to squeak into the playoffs, albeit with a record five games under .500—the first of 13 straight seasons without a winning record. The WHA had collapsed going into that season and the absorption of the four surviving teams ensured the Leafs would still limp into the playoffs.
Imlach named assistant Joe Crozier as his successor as coach after the season.