The Super Eagles play the Seychelles in their last Africa Cup of Nations qualifier on March 22 then take on Egypt in a friendly four days later.
Nigeria are top of Group E on 10 points ahead of South Africa on 9, Libya on 7 and Seychelles on 1pt, with this weekend’s match concluding the preliminary group round.
Both matches are due to be played in the southern city of Asaba.
Team spokesman Toyin Ibitoye said youth team captain Ikouwem Udoh, 19, would replace 21-year-old Kalu, whose mother was recently kidnapped and held for a week until a ransom was paid.
Udoh, who plays for club side Enyimba, is a left-back who has played for Nigeria’s home-based team, which lost in the final of last year’s African Nations Championship to Morocco.
Nigeria coach Gernot Rohr has said he is keen to get more left-sided players into the squad in the run-up to the AFCON tournament in June.