Sturridge, who spent time with the centre-back while on loan at Bolton a season ago, has said that Cahill has strong all-around skills and is more than capable of going straight into the starting lineup for the side's trip to Carrow Road this weekend.
"He has settled in very well very quickly and shown his qualities on the training field," Sturridge told the club's official website. "The lads have made him feel very welcome.
"Gary is very good on the ball, very comfortable, very strong and has good speed. He has everything you need as a centre-half and when I was at Bolton he played some great balls for me from the back – it's good to get him here.
"He's a very nice guy and a great addition to the squad."
Cahill made over 120 appearances for Bolton in four seasons at the club after arriving from Aston Villa.