The host country will be represented by Yanga and Azam FC, who completed the 2020/21 Vodacom Premier League season in second and third place, respectively, while Simba SC, which reached the quarterfinals of the CAF 2020/21 CAF Champions League, will not take part.
There is no official reason given by Simba SC not to be involved in Kagame Cup.
In an earlier statement, Simba SC and Biashara United were reportedly involved as part of the competition.
While Yanga will participate in the next season's CAF Champions League, Azam FC will represent Tanzania in the CAF Confederation Cup.
This season's Kagame Cup is set to give them a platform to test themselves against other regional clubs.
The CECAFA Executive Director, Auka Gecheo, said the competition's draw will be conducted on July 27.
The showdown is geared towards helping participants prepare for CAF competitions.
"This tournament will help our teams in the region prepare for the Caf competitions that start in September. We shall also have a guest team from Malawi to spice up the tournament," Gecheo said.
Gecheo added: ''This tournament will help our teams in this region prepare for the CAF tournaments which will start in September."
''We will also have a foreign team from Malawi to promote the tournament,'' the official noted.
Uganda will be represented by KCCA FC, the showdown's defending champions, and champions of the Uganda Premier League 2020/21, Express FC.
Kenya's CAF Champions League representatives have confirmed they will be part of the August competition.
Gecheo confirmed that Malawi's Premier League side, Big Bullets FC, will take part in the tournament.
The KCCA FC defeated Azam FC in the Kagame Cup's final in 2019 and won the trophy.
Last year the tournament did not take place after the COVID-19 pandemic affected many sports activities, including soccer.
Teams certified to participate in Kagame Cup 2021 are Yanga, Azam FC (Tanzania), Altabara FC (South Sudan), Le Messager Ngozi FC (Burundi), APR (Rwanda), Express FC, KCCA FC (Uganda), Tusker FC (Kenya)), KMKM SC (Zanzibar), and Big Bullets FC (Malawi).
The regional club competition will begin just after the completion of the CECAFA U-23 Challenge Cup, which is taking place in the northern city of Ethiopia, Bahir Dar.