England coach Eddie Jones says three places are up for grabs before he slims his 38-man World Cup training group to a final squad of 31 on August 12.

Jones has also implored those who missed out on the squad to be England’s version of Stephen Donald — the All Blacks fly-half who was parachuted in from a fishing trip to kick a decisive penalty in the 2011 World Cup final.

Joe Marler’s retirement reversal was the most surprising call in Jones’s training squad but four uncapped players made the squad, too — Willi Heinz, Lewis Ludlam, Jack Singleton and Ruaridh McConnochie. Mike Brown and Dan Robson were the notable absentees.

Jones will name his final squad after the first of four warm-up matches in August and September, much earlier than he needs to.

He revealed there is a chance players who missed out on the 38-man squad will be invited into the camps he is holding in Bristol and Treviso.

“I’ve got an open-door policy. We want to keep on making sure we get the right squad for Japan. We’ve got a pretty good idea of where we are,” said Jones, before revealing there are probably three spots up for grabs.

“Everyone has to be ready. In 2011 Stephen Donald was out whitebaiting. And then he got the call from Graham Henry and ended up landing the goal that won the World Cup.”

Jones has shed plenty of experience in his squad by leaving out Brown, Chris Robshaw and Danny Care, while also losing former captain Dylan Hartley to injury. He has been out since December with a knee injury that “is just not repairing”.

“He is still doing everything he can to get himself right,” said Jones.

“Someone from the team will speak to him on a weekly basis, so we’ve got updates.”