The two were part of the team that played out to a barren draw with Esperance of Tunisia in the opening leg on March 7 at Machakos Stadium.
Also dropped from the travelling party is Bernard Ondiek whose place has been taken by Cercidy Okeyo, signed from Tusker last January.
Omondi and Ivorian striker Guikan have been replaced by Joash Onyango and Charles Momanyi.
According to the list in possession of Goal, Dylan Kerr will depend on the firepower of the Rwandan duo Jacques Tuyisenge and Meddie Kagere for goals when K’Ogalo steps to the pitch on Sunday.
Former Tusker midfielder, Humphrey Mieno and Lawrence Juma are also expected to make the trip. K'Ogalo are set to depart the country for Tunisia on Thursday midnight.
Gor Mahia travelling squad: Meddie Kagere, Boniface Omondi, Charles Momanyi, Jacques Tuyisenge, Wesley Onguso, Francis Kahata, Samuel Onyango, Haron Shakava, Joakim Oluoch, Shaban Odhonji, Philemon Otieno, Boniface Oluoch and Earnest Wendo.
Others are; Lawrence Juma, George Odhiambo, Bernard Ochieng, Humphrey Mieno, Cercidy Okeyo, Godfrey Walusimbi and Joash Onyango.