Dutch international Khalid Boulahrouz has completed his move from Hamburg to Chelsea after the defender passed his medical and agreed personal terms with the London club.

The transfer fee has not been disclosed by the clubs but is thought to be in the region of £6million. Boulahrouz, 24, is known for his versatility and can play anywhere across the back-four. He watched Chelsea's 3-0 win over Manchester City in their Premiership opener yesterday.

Boulahrouz is available for Chelsea's European campaign because he was a non-playing substitute in Hamburg's Champions League qualifier against Osasuna. The Dutchman, who started his career at RKC Waalwijk, is 5ft 9ins but his reputation for fierce tackling earned him the nickname "Khalid the Cannibal".

He will go straight into Chelsea's squad for Wednesday's game at Middlesbrough. Jose Mourinho is short of defenders with only Paulo Ferreira, Ricardo Carvalho, John Terry and Wayne Bridge available for the City game.

Geremi and Robert Huth are injured and William Gallas has been frozen out since returning late for pre-season and talking publicly about his desire to leave. Terry played despite a slight groin problem, which was causing him discomfort towards the end of the game.

Mourinho said: "In a short squad and, in a country where you can have only 16 players in a match, it's important to have cover for many positions.

"Now I have three options for the centre - Ricardo, Boulahrouz and John Terry. I can have Paulo or Boulahrouz on the right side and I can have Wayne Bridge or Boulahrouz on the left."

The arrival of Boulahrouz will not end Chelsea's long-running pursuit of Ashley Cole.