Bournemouth are unsure how long Alex Scott will be out for with his latest knee injury, says head coach Andoni Iraola.
The 20-year-old midfielder was forced off during last weekend's 6-1 defeat at Manchester City.
Scott signed for the Cherries from Bristol City in the summer for £25m and has only just returned after problems with his other knee.
Iraola said Scott's injury is a medial collateral ligament sprain.
Scott looked to be running off a dead leg when he fell to the ground in pain following a block tackle by City midfielder Rodri just before half-time.