Taifa Stars host Kenya's Harambee Stars in the first leg of the qualifiers and Kaseja believes a combined team effort and support from fans will help the host team get the win they need.
"We cannot just talk of an individual as one player can not carry the whole team. We need unity and effort from each player now both off and on the pitch, because this is a team for all Tanzanians," Kaseja told East African TV.
"We have the opportunity to win because even the relatively new players would not be playing this kind of a match for the first time as they have played at various international levels. What I insist is unity between players and the Tanzanians in general in supporting the team."
Kaseja, who is currently with KMC FC, was the undisputed Taifa Stars goalkeeper between 2001 and 2007 before he fell out of favour despite a 2009 recall.