The two players will join the side in February pending an approval from the USL Championship and USSF.
Donsu, who joined the Mauve and Yellows in 2013, has been an integral part of the side.
The dead ball specialist has scored 22 goals in 39 appearances for the side in the past two seasons.
Yaro is a stalwart centre back who recently featured for the Ghana U23 team in the 2019 CAF U23 Cup of Nations qualifiers against Togo.
We wish them well! pic.twitter.com/YZw0YVm40g
— Medeama SC (@MedeamaSC) January 10, 2019