Sheffield Wednesday took full advantage of relatively new rule during their League One with Morecambe on Tuesday night.
Plenty of fans, journalists and onlookers were slightly puzzled when the hosts brought on Saido Berahino in the 73rd minute.
He came on to replace the injured Josh Windass, but it wasn't the presence of the former Stoke and West Brom man that caused plenty of confusion.
It was more the fact that Berahino was the fourth change made by the Owls... despite them only being allowed to make three.
But, after the game it was confirmed by Wednesday assistant boss Jamie Smith that his side were in fact able to make four changes due to the fact that a Morecambe player had been taken off for concussion.
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Smith, standing in for boss Darren Moore who tested positive for Covid-19, clarified the situation when quizzed post-match following the 2-0 win for Wednesday.
He said: "We made four substitutions today and that was due to their goalkeeper coming off as a concussion sub.
"It meant we could make an additional one ourselves."
New rules brought in for this season have allowed teams to make two 'concussion subs' during any given match, in an attempt to alleviate any time pressure and allow all head injuries to be correctly examined.
The rules state that in the event of one team having to make a change due to clear symptoms of concussion - or clear video evidence thereof - the opposing team will also be allowed to make an additional substitution at a time of their choosing.
Morecambe goalkeeper Trevor Carson suffered concussion midway through the first half at Hillsborough, with Kyle Letheren coming off the bench to deputise.
The rule was also used earlier this season in a Championship clash between Cardiff and Hull.
The new rules brought in for this season include a reverting back to the traditional three subs rule, despite teams having been able to make use of five subs following the return to action during the Covid-enforced hiatus.
The decision came despite the International Football Association Board (IFAB) opting to extend the five-substitution rule until the end of the 2021-22 campaign.
As a result, teams in the EFL may choose three subs from a bench of seven.
Premier League clubs are permitted to select a nine-man bench but can only make a maximum of three changes, not including concussion subs.
Wednesday sealed a third straight home win thanks to second half goals from George Byers and Nathaniel Mendez-Laing.
It continued their fine run on home soil, having lost just once in the league at S6 all season. They are now just four points off the play-offs with a game in hand.
Giving an update on Moore's absence, Smith said: "He's absolutely fine, just a sore throat.
"He was in constant contact during the game, he was delighted with the win. There's nothing that should keep him away longer than his regular quarantine."
Last year Moore spoke about his well-documented struggles with Covid, saying he was "fighting for my life" during a lengthy battle with the respiratory condition.
