Former All Black Charles Piutau and Ireland's Bundee Aki have been ruled out of the Barbarians' clash against England at Twickenham on Sunday.
New Zealand international Piutau suffered an Achilles tendon strain ahead of Ulster's European Champions Cup play-off victory against the Ospreys on Sunday.
And Ireland centre Aki, who was due to captain the Baa-baas against England, is nursing an ankle injury.
The Barbarians also announced that Sale Sharks fly-half AJ MacGinty has been withdrawn from the squad by his club.
Baa-baas head coach Pat Lam has now finalised his group for the England encounter, adding five more players in Scotland fly-half Finn Russell, New Zealand centre Malakai Fekitoa, Newcastle and Fiji centre Josh Matavesi, his Falcons colleague, flanker Nili Latu, and Connacht prop Denis Buckley.
"It's unfortunate that Charles Piutau strained an Achilles tendon warming up for Ulster on the weekend, Bundee Aki rolled an ankle in training in Galway and AJ MacGinty has been pulled out by his club," said Lam.
"But it's great that we are able to call in some more quality players."
The Barbarians starting line-up is due to be announced on Thursday.
All Black Charles Piutau has been ruled out of the Barbarians' clash against England