Alex McLeish says Blues have enough defensive cover (Getty Images)

Kapo is likely to be out for about a month after suffering a hamstring problem against Arsenal.

Ridgewell was limping near the end of last Saturday's draw after sustaining an ankle problem.

"Ridgewell is doubtful for the Spurs game. He'll train on Friday and we will make a final decision on Saturday," McLeish told his club's website.

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Kapo had to be substituted early in the second half of the 2-2 draw with Arsenal.

"I think playing with 10 men put an extra strain on all of the players," said McLeish. "Kapo was key for us in the first half because he provided a great outlet for Maik Taylor. He also won an awful lot of balls in the air for us and kept the ball alive for us in the first half.

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"Unfortunately I think the extra burden that it put on him in particular has taken its toll."

McLeish also insists he has sufficient defensive cover to cope if Ridgewell is ruled out.

"Stephen Kelly went into the centre of defence and had a fantastic game," the Blues manager told BBC WM.

"We've also got as options Radhi Jaidi or Rafael Schmitz, so we do have players who can cover.