Chesterfield's play-off push has been dealt a major blow as veteran striker Jack Lester has been ruled out for up to six weeks.
The 34-year old, who is the Spireites' top scorer this season, requires an operation on his right knee after a tear of his cartilage was discovered.
Lester had been missing for the club's last two games, in which they nonetheless obtained back-to-back wins, and that tally could now rise to six.
Chesterfield currently linger just outside the play-off positions in seventh place, with seven of Lester's eight strikes this term coming in League Two.
Meanwhile, boss John Sheridan will also be without defender Phil Picken who suffered a knee ligament strain in training, sidelining him for around three weeks.
On the plus side for the Saltergate boss, striker Drew Talbot is back in contention for Saturday's visit of Bury after overcoming an ankle injury.