Norwich City manager David Wagner has played his part in one of Birmingham City’s relegation battles before.

The German was Huddersfield Town’s manager in 2017 when the Terriers were defeated 2-0 by 10-man Blues in the penultimate game. The win put Blues on course for survival on the final day of the 2016/17 season at Bristol City.

It landed Wagner in hot water with the EFL, though, after he made 10 changes to his starting line-up. Wagner opted to rest players with Huddersfield’s place in the play-offs – which they ultimately won – already secured.

The EFL held lengthy meetings but found no grounds to punish Wagner or Huddersfield because their rules didn’t define what a ‘full strength team’ actually was. The rules state: “Each club shall play its full strength team in all matches played under the auspices of The League unless some satisfactory reason is given. In the event of the explanation not being deemed satisfactory the Board shall refer the matter to a Disciplinary Commission which has the power to impose such penalties as it shall think fit.”

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That game set the precedent for the EFL to make a change to its rules. It now states: “For any league match played on or after the fourth Thursday in March, any team sheet for a league game should include at least 10 outfield players who featured on the team sheet for the league match before.”

Because teams are now permitted nine substitutes, the rule change won’t prevent Wagner from making wholesale changes. He could change the majority of his XI as long as the squad includes 10 outfield players that were involved against Swansea City last time out.