Bournemouth boss Andoni Iraola says Tyler Adams has suffered from past surgery.
The summer arrival from Leeds has just undergone a fresh operation on his hamstring injury.
Iraola confirmed: "Surgery was in Finland, different specialists, past surgery was not successful, [he] wasn't feeling 100%, now he has the need to start again from zero. Out for three, four months, once he's with us he'll be 100%.
"It was something the club studied very well, specialists, we know that Tyler was in a tough spot.
"When you sign a player there are different things going on and difficult decisions to take but even with injuries it's very good for us to have a player like Tyler playing for Bournemouth."