Wolves' Bakary Sako has revealed he is mulling over offers from the Premier League but is yet to decide on his future.
Rotherham boss Steve Evans will decide the fate of his out-of-contract players in a meeting on Monday.
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.