Concussion Substitute Controversy — Marnus for Smith

During the second Ashes Test at Lord's, Steve Smith was struck on the neck by a fearsome Jofra Archer bouncer. Smith initially continued batting but was later ruled out of the rest of the match with delayed concussion symptoms.

Marnus Labuschagne was called in as cricket's first-ever concussion substitute, a rule introduced by the ICC only weeks earlier. England's concern was whether Labuschagne — who would go on to become the world's number-one ranked Test batsman — was truly a "like-for-like" replacement for a player who had been batting at number 4.

Labuschagne came in and was immediately hit on the grille by Archer on his first ball. He survived and scored 59 in the second innings, playing a crucial role. The match ended in a draw.

The incident raised important questions about the concussion substitute rule: Who decides if it's like-for-like? Could teams game the system by replacing a struggling bowler with a specialist? While Smith's concussion was genuine, the rule's potential for exploitation became a topic of intense debate.