Christopher Nkunku undergoes knee surgery as Chelsea ponder emergency striker signing

New Chelsea striker Christopher Nkunku has undergone surgey on a knee injury, ruling him out of the start of the season.

The Blues kick off their campaign against Liverpool on Sunday with their £52million signing expected to be out for a period of months.

Nkunku, 25, injured his knee in the pre-season friendly against Borussia Dortmund and has undergone scans in recent days to determine the size of the issue.

After being diagnosed with a meniscus injury, the Frenchman underwent the operation as the club confirmed his absence.

A statement read: “Nkunku has sustained a knee injury which will rule the forward out for an extended period.

“The 25-year-old has undergone an operation and will now begin a rehabilitation programme with the club’s medical department.”

Chelsea are considering signing a new striker to increase Mauricio Pochettino’s options up front.

The club also reacted quickly to a long-term injury for defender Wesley Fofana, by signing Axel Disasi from Monaco for £39m.

Juventus forward Dusan Vlahovic has been linked with a move to Stamford Bridge, as part of a player-plus-cash deal that could see Romelu Lukaku head in the opposite direction.

Wantaway Paris Saint-Germain attacker Kylian Mbappe has also been subject to discussions, according to reports.