Governing body World Rugby has handed Wales an official warning after it was discovered that players from outside their 31-man squad were taking part in training sessions, but Warren Gatland is not sure what he’s done wrong.

Under the current rules, any player not in the World Cup squad is not allowed at training sessions, but Reuters report that Nicky Smith, Rob Evans, Rhys Patchell, Dan Baker and Kristian Dacey have been working with Wales.

“While World Rugby is satisfied that no deliberate breach was intended, an official warning has been issued to the WRU,” a statement said.

“All participating teams have been informed that additional players from the extended squad, including potential injury replacements, may not be included in any training sessions.”

Wales’ squad has been blighted by injuries in recent weeks, with Tyler Morgan called into the squad this week to replace Cory Allen, who scored a hat-trick in the first game against Uruguay.

But Gatland said at Thursday’s press conference admitted that he is confused as to exactly what rules his squad are said to have broken.

“We haven’t broken any rules,” he said. “Apparently we have broken the ‘spirit of the rules’. What that means we don’t know… I don’t know what we have done wrong.”

Coach Warren Gatland named his team to face England on Saturday, with the Kiwi selecting Gareth Davies at scrum-half and leaving Mike Phillips out of the 23-man squad.