Prop Joe Marler has come out of retirement to be included in England's Rugby World Cup training squad, while fly-half Danny Cipriani has retained his place despite another shake-up of personnel by head coach Eddie Jones.
Harlequins forward Marler, 28, retired from international rugby last September citing personal reasons, but has reversed his decision in time to make a bid for a place in the final squad that will head to Japan in September.
Elsewhere Gallagher Premiership winners Saracens and finalists Exeter Chiefs have returned their players after a five-week break, among them co-captain Owen Farrell, lock Maro Itoje, centre Henry Slade and No. 8 Billy Vunipola.
There are four uncapped players in the 35-man squad -- Gloucester captain and scrum-half Willi Heinz, Northampton Saints forward Lewis Ludlam, Bath winger Ruaridh McConnochie and Jack Singleton of Saracens -- but there are also notable absentees with Dylan Hartley still not recovered from a knee injury and experienced Harlequins trio Danny Care, Mike Brown and Chris Robshaw left out.
Surprise inclusion Marler last played for England in a Test match defeat to South Africa in June 2018 but had told Jones he was interested in a return when he played for the Barbarians against England last month.
"I saw Joe during the Barbarians' week and he indicated that he had a desire to come back," Jones said. "We have since had a couple of chats and we have given him the opportunity to do that. Now it is up to him to show us what he has got."
Cipriani, who was named Premiership and Rugby Players Association Player of the Year after a superb campaign with Gloucester last season, has impressed sufficiently since joining up with the last training camp to keep his place.
The 31-year-old last played for England at the same time as Marler, against South Africa in June 2018, but will be encouraged to have kept his place despite the influx of talent from Premiership finalists Saracens and Exeter Chiefs.
But with competition fierce at fly-half and only 31 places in Jones' final squad, which will be decided at the beginning of September, Cipriani will have to compete for a place.
"We can't wait to have the full squad in place and to have players competing for those 31 places," Jones said. "It is a process of building the team up, building the cohesion, the tactical understanding of the team and our adaptability. We will need to get those things right to win the World Cup, and that is our aim."
Three players who were involved in the Premiership final -- George Kruis (lock), Jack Nowell (wing) and Mako Vunipola (prop) -- are still being considered for selection as they undergo treatment for injuries during the camp, but Harlequins prop Kyle Sinckler has been declared fit after leaving the last training camp with a hamstring injury.
His front row colleague and England co-captain Dylan Hartley looks set to miss the tournament after again failing to overcome a long-term knee injury. Hartley has not played since December and is rapidly running out of time to prove his fitness.
Veterans Care, Robshaw and Brown -- England's most capped full-back -- are the headline absentees from the squad alongside Wasps scrum-half Dan Robson, who impressed during the Six Nations but was then ruled out after suffering blood clots.
"World Cup selection is a four-year process," Jones added. "We have looked at the squad carefully, tried to build up a squad that has enough experience, attitude and energy to be winners and I think we have that. In the process, we have left out some players who can feel unlucky."
England have already conducted two mini camps during the summer where Jones has been able to assess 34 players in preparation for the World Cup.
The head coach now has the chance to see some of those names in action in warm-up matches against Wales (twice) and Ireland in August.
Jones will name a final 31-man World Cup squad before the deadline of Sept. 2, then England take on Italy in their final warm-up game.
The tournament begins on Sept. 20, with England opening their campaign against Tonga two days later. They will also face France, Argentina and USA in Pool C.
Information from Reuters contributed to this report.
England training squad
Dan Cole (Leicester Tigers, 85 caps) Luke Cowan-Dickie (Exeter Chiefs, 11 caps) Tom Curry (Sale Sharks, 10 caps) Charlie Ewels (Bath Rugby, 10 caps) Ellis Genge (Leicester Tigers, 9 caps) Jamie George (Saracens, 37 caps) Maro Itoje (Saracens, 27 caps) Joe Launchbury (Wasps, 58 caps) Courtney Lawes (Northampton Saints, 71 caps) Lewis Ludlam (Northampton Saints, uncapped) Joe Marler (Harlequins, 59 caps) Ben Moon (Exeter Chiefs, 8 caps) Brad Shields (Wasps, 8 caps) Kyle Sinckler (Harlequins, 22 caps) Jack Singleton (Saracens, uncapped) Sam Underhill (Bath Rugby 9 caps) Billy Vunipola (Saracens, 41 caps) Harry Williams (Exeter Chiefs, 17 caps) Mark Wilson (Sale Sharks, 13 caps)
Danny Cipriani (Gloucester Rugby, 16 caps) Joe Cokanasiga (Bath Rugby, 4 caps) Elliot Daly (Saracens, 30 caps) Owen Farrell (Saracens, 70 caps) George Ford (Leicester Tigers, 55 caps) Piers Francis (Northampton Saints, 4 caps) Willi Heinz (Gloucester Rugby, uncapped) Jonathan Joseph (Bath Rugby, 40 caps) Jonny May (Leicester Tigers, 45 caps) Ruaridh McConnochie (Bath Rugby, uncapped) Henry Slade (Exeter Chiefs, 22 caps) Ben Spencer (Saracens, 3 caps) Ben Te'o (unattached, 18 caps) Manu Tuilagi (Leicester Tigers, 32 caps) Anthony Watson (Bath Rugby, 33 caps) Ben Youngs (Leicester Tigers, 85 caps)
In camp for rehabilitation
George Kruis (Saracens, 32 caps) Jack Nowell (Exeter Chiefs, 33 caps) Mako Vunipola (Saracens, 53 caps)