Bournemouth's record signing Tyrone Mings has been ruled out for the season after suffering a knee injury on his Premier League debut in Saturday's 1-1 home draw with Leicester.
Winger Max Gradel, who also suffered a knee injury in the same game, is out for six months, with Bournemouth confirming the double setback on their official website.
Both players have been left off the 25-man squad list submitted by the south coast club for the first half of the Premier League season.
The Cherries confirmed that Mings, signed from Ipswich for a reported £8 million, would undergo surgery next week after tearing his medial and anterior cruciate ligaments.
He wrote on Twitter: "Very tough pill to swallow ... but I've been through tougher. I'll be back."
Very tough pill to swallow ... But I've been through tougher, it's only a knee at the end of the day. I'll be back ���� pic.twitter.com/I6vt2STfxi
- Tyrone Mings (@OfficialTM_3) September 4, 2015
Gradel ruptured his left anterior cruciate ligament and has had an operation.
Manager Eddie Howe told Sky Sports: "Max will be out for pretty much six months.
"He's had his operation and is recovering now. Tyrone will be out for at least nine months.
"I feel for the players more than anyone. I'm really disappointed for them that they're both going to be out for long periods.
"Both players are positive about the future, and we will look after them and back them.
"It's a big blow, but we have to recover and it will be an opportunity for somebody else."
Gradel, who has featured in all four of Bournemouth's Premier League games this season since joining for a reported £7m, was sidelined with a similar injury in 2013.
Bournemouth made three new additions to their squad on transfer deadline day -- Glenn Murray was signed from Crystal Palace, while Tomas Andrade and Joe Bennett joined on loan from River Plate and Aston Villa respectively.
Their arrivals took the club's total number of signings for the summer to 12, with Mings and Sylvain Distin among the other new additions.