Veteran winger Ainsworth played the full 90 minutes in the 2-1 defeat to Accrington on Saturday, but struggles to play twice in four days and could be put on the bench.
Kevin Betsy is one option to replace Ainsworth. Betsy missed out on the home defeat at the weekend with a hamstring strain but could make his return if he passes a late fitness test.
Midfielder Matty Bloomfield pulled his hamstring at Southend last week and is set to be out of action for around a fortnight but Jon-Paul Pittman is back in contention after recovering from the knee injury he sustained in September.
Defender Chris Westwood is out with a groin injury while left-back Andy Sandell is still sidelined with a knee injury that is expected to keep him out for a minimum of six weeks.
Source: PA
Source: PA