"Blues have today completed the loan signing of Argentinian striker Mauro Zarate from Qatari side Al-Sadd," read a club statement.
"The Under-20 international joins the club until the end of the current season.
"Blues are hoping to be able to play Zarate in this evening's (Monday's) reserve game against Arsenal at St. Andrew's, but that is dependent on international clearance being received by 5pm."