The Women’s Super League says an investigation is under way after Crystal Palace used four substitution windows in their win over Everton.

A statement says that Palace “breached” the rules, adding that they only permit a maximum of three substitution opportunities per match.

The Eagles made four separate substitutions in the 62nd, 83rd, 90th and 97th minute of Sunday’s 1-0 victory at the Borough Sports Ground.

The league confirmed the investigation will involve both clubs and referee body Pro Ref.

WSL rules do not prescribe an automatic punishment but any breach could be referred to an independent tribunal, which has the power to impose sanctions ranging from a warning or fine to a points deduction or other sporting sanction.

Both clubs have been approached for comment.