England head coach Eddie Jones says the decision to leave Danny Cipriani out of England's 36-man training squad was based on the fly-half's form.
Cipriani was arrested during a pre-season night out with his Gloucester teammates in August and was subsequently charged by the RFU for conduct "prejudicial to the interests of the game."
No further action was taken by England Rugby's governing body and the 30-year-old was expected to be named in Jones' training camp after his fine start to the Premiership season, especially after the England head coach said Cipriani would be judged for his "performances on the pitch".
But Jones, who started Cipriani during England's tour of South Africa in June, has decided to omit the fly-half from his three-day camp, which assembles in Bristol on Sunday Sept. 23.
"He has some areas of the game he needs to work on and he has the next three games to show that," Jones said at a press conference at Twickenham on Thursday.
"We decided just to have two stand-offs in the squad for this particular camp because we want them to get a lot of training time and Danny is probably third or fourth, and he knows what he has to work on.
"We've got Owen [Farrell] and George [Ford] who I believe are our first two fly-halfs and then comes Danny.
"He [Cipriani] was disappointed but he understands. He's desperate to play for England," Jones added.
The camp is being used by England to prepare for November and December's Autumn Tests. A separate squad for the fixtures, which includes home matches against South Africa and New Zealand, is set to be announced in late October. Elsewhere, Ashton and Tuilagi are the headline names to have been included.
Ashton, who is eligible for selection again after moving back to the Premiership in the summer, has yet to play this season after being sent off for fighting in a pre-season friendly in August. The winger was banned by the RFU for seven weeks following the incident and has not played for England since 2014.
Tuilagi has been included in an England squad for the first time in over a year after impressing on his latest comeback from injury for Leicester. The centre has not played for his country since the 2016 Six Nations and underwent further knee surgery during the summer, but has appeared three times for his club so far this season.
Danny Care, George Kruis, Zach Mercer and Jack Nowell have all been recalled to the squad after sitting out England's tour of South Africa earlier this year.
Full Squad
Forwards: (20) Tom Curry (Sale Sharks), Jamie George (Saracens), Dylan Hartley (Northampton Saints), Nathan Hughes (Wasps), Nick Isiekwe (Saracens), Maro Itoje (Saracens), George Kruis (Saracens), Joe Launchbury (Wasps), Courtney Lawes (Northampton Saints), Joe Marler (Harlequins), Zach Mercer (Bath Rugby), Michael Rhodes (Saracens), Chris Robshaw (Harlequins), Nick Schonert (Worcester Warriors), Brad Shields (Wasps), Kyle Sinckler (Harlequins), Billy Vunipola (Saracens), Mako Vunipola (Saracens), Harry Williams (Exeter Chiefs), Mark Wilson (Newcastle Falcons).
Backs: (16) Chris Ashton (Sale Sharks), Mike Brown (Harlequins), Danny Care (Harlequins), Joe Cokanasiga (Bath Rugby), Elliot Daly (Wasps), Nathan Earle (Harlequins), Owen Farrell (Saracens), George Ford (Leicester Tigers), Alex Lozowski (Saracens), Jonny May (Leicester Tigers), Jack Nowell (Exeter Chiefs), Dan Robson (Wasps), Henry Slade (Exeter Chiefs), Ben Te'o (Worcester Warriors), Manu Tuilagi (Leicester Tigers), Ben Youngs (Leicester Tigers).