England suffer another blow ahead of SA tour
England centre Joseph, 26, is to undergo surgery on a foot injury he suffered in Bath's 6-41 Premiership defeat to Saracens last Sunday.
Joseph, whose predatory instincts have brought him 17 tries in 40 Tests, will also require a long period of rehabilitation.
"JJ is going to need surgery to correct his injury," Bath's Rugby Director Todd Blackadder told the club's website.
"He will then need a lengthy period of time to rehabilitate. Our medical team will work closely with him to ensure we get him back on the pitch as soon as possible."
Jones could dearly do with Joseph's try-scoring ability as he bids to get England back on a winning path again following an underwhelming defence of their Six Nations crown which saw them lose three successive matches.
Anthony Watson, also of Bath, is already sidelined from the tour because of an Achilles' injury, and captain Dylan Hartley is believed to be a doubt due to concussion.
Knee injuries, meanwhile, look set to remove lock Courtney Lawes and No.8 Nathan Hughes from the South Africa tour which includes Tests on June 9, 16 and 23.
England last toured South Africa in 2012 losing the first two Tests before drawing the final match.