The central defender, who has headed out for three extended loan spells since joining in August 2004, got to make his first start against Manchester United on Monday following on from his substitute appearance in the 1-0 win over Everton on Saturday.
His only previous first team run-out in our colours came in attack as a substitute against Aston Villa in November 2005 on his return from his spell at West Ham. He later enjoyed stints at Southampton and Norwich City.
Calum was an impressive figure in the heart of our defence alongside Michael Dawson when given the call due to injuries to Ledley King and Anthony Gardner. Strong in air and comfortable on the ball, the recruit from Coventry City showed the fans what he can do by bringing the ball out from the back and linking up with attack.
"I was delighted for Calum and he has waited a long time for his chance," said Robbie, captain in the absence of Ledley. "Against Everton he did ever so well when he came on, it is not easy marking Duncan Ferguson and James Beattie. He won nearly every header.
"Monday was his first start for us and I thought he and Daws were brilliant.
"For two young lads it is never easy - especially with the two United have up front - but they stepped up.
"Hopefully now they can continue that," continued Robbie, who went on to offer his reaction to the injury news on the skipper.
"Obviously it is a big blow to lose Ledley and we all wish him well. Hopefully he gets fit in time for the World Cup because Ledley will be desperate to play some part and be involved in the squad.
"It is a blow for us, but luckily enough, we have players who can come in and do a job hopefully as well as Ledley has."
Robbie Keane was full of praise for the displays of Calum Davenport over the Easter programme.