Chesterfield have won just one of their last five against Pompey (D1 L3).
Portsmouth have been on the winning side just once in their last 11 away League Two fixtures (D6 L4).
Chesterfield have scored in each of their last seven home games, a run only bettered by Burton (9) currently.
Of the players to score four or more times, only Sam Winnall (144 minutes) has a better minutes per goal ratio than Jake Jervis this season (150).
Before this weekend, the Spireites had collected 20 points in 2014, more than any other side.
Pompey have conceded 31 second-half goals this season, a League Two high.