LuaLua was injured towards the end of last season too

The 25-year-old, who signed a three-year contract last week, will have a scan on Monday.

"The swelling suggests a fair bit of damage," said Portsmouth physio Gary Sadler after the game.

LuaLua added: "You don't know how gutted I am. Two weeks before the start of the season, can you believe it?"

The injury leaves boss Harry Redknapp with just Svetoslav Todorov and �4.1m record signing Benjani Mwaruwari as his senior striking options.

He may be forced to enter the transfer market following LuaLua's injury but has made little progress in his bids for Tottenham striker Jermain Defoe and Fenebache's former Arsenal forward Nicolas Anelka.