Fiorentina winger Juan Cuadrado has made it clear he wants to join Chelsea, Sky sources understand.
The club confirmed today that Boyd had signed a one-year contract and Gros had penned a deal that ties him to Rugby Park for three years.
Former Rangers striker Boyd, 29, hit three goals in eight league appearances after rejoining Killie in February following a spell in the United States with Portland Timbers.
Frenchman Gros has netted two goals in 40 appearances since joining the club in 2010.
The 21-year-old had been linked with a move to Oldham, who are managed by former Killie midfielder Lee Johnson.