The EFL Championship playoffs are heating up—but not just on the pitch. Southampton FC is under investigation after allegations that one of their staff members was caught spying on Middlesbrough's closed training session ahead of their playoff semifinal first leg.

The English Football League confirmed it has launched a probe into the incident, which reportedly took place on Thursday morning—just two days before Saturday's crucial matchup at the Riverside Stadium. According to BBC Sport, a Southampton performance analyst was allegedly spotted recording Middlesbrough's training drills and photographing tactical setups. The individual was reportedly asked to delete the footage and leave the premises immediately.

"The EFL has written to Southampton FC requesting their observations following a complaint from Middlesbrough FC relating to alleged unauthorized filming," an EFL spokesperson told the Southern Daily Echo. "The alleged incident is said to have taken place on Middlesbrough’s private property by an individual identified to be associated with Southampton."

Under EFL regulations, clubs are strictly prohibited from observing—or attempting to observe—another team's training session within 72 hours of a match. The league is treating this as potential misconduct and has stated it will make no further comments while the investigation is ongoing.

This isn't the first time playoff football has been rocked by off-field drama, but for fans and players alike, the focus remains on the action. With the stakes sky-high in the Championship playoffs—where promotion to the Premier League and its financial rewards await—every edge matters. But as this incident shows, some lines should never be crossed.

Stay tuned for updates as the EFL continues its investigation, and remember: whether you're on the pitch or in the stands, fair play is always in style.