The Spireites fielded six players who are trying to earn a deal at the Proact Stadium in their 2-1 pre-season win over Huddersfield, including goalscorer Jamie Devitt.
The former Hull winger, who had a loan spell at Rotherham last season, is in pole position for a contract, while Cook will also ponder the future of Ritchie Humphreys, Matty Brown, John Shaw, Conor Clifford and Hendrick Cakin.
Cook's first-team coach Kevin Lynch told the club's official website: "Jamie has got that in his locker. We're still looking at him and he's done his chances no harm.
"On the others I think there are some tough decisions that the gaffer has got to make."