Northampton could be fined after accepting that they are “outside Premiership Rugby board policy” for releasing Wales wing George North to play in Saturday’s Test match against Australia, which falls outside the international window.
Though Saints argued that their agreement with North has “not contravened any rules, laws or regulations”, they are likely to be investigated by Premiership Rugby – and could be hit with a five-figure fine.
The Australia game falls outside the International Rugby Board’s official autumn window and Premiership Rugby’s policy states that no non-England players should subsequently be released for matches or training camps.
That policy was agreed by all 12 Premiership clubs, with any breaches governed by a code of conduct.
Bath prop Paul James has returned to the Recreation Ground this week, while Perpignan players James Hook and Luke Charteris have also left the Wales camp to rejoin their club. North, 21, moved to Northampton from the Scarlets earlier this year.
The IRB is also taking steps to avoid a repeat of the scenario where England face New Zealand in the first Test of next year’s summer tour with a weakened team.
Stuart Lancaster’s side open the series on 7 June, just seven days after the Premiership final is staged at Twickenham. The proximity of the dates means head coach Lancaster is resigned to being unable to field his first-choice starting XV until the second Test on 14 June.
The IRB chief executive Brett Gosper said: “It’s the product of a crowded season. These calendars were decided some years ago. We’re looking at the windows at the moment to see if we can find a better balanced calendar.”
Wales international lock Ian Evans will join Heineken Cup holders Toulon on a three-year contract this summer.