Full-back Richardson has missed the last three games with a groin injury and is unlikely to make his comeback against the Gulls.
On-loan Burnley centre-back Long sat out the 3-2 midweek victory over Crewe and may miss out again.
Coleman has no other worries and could name the same starting line-up following two successive victories, although winger Sean McConville is pushing for a recall after stepping off the bench against the Railwaymen before netting the winning goal just three minutes later.
Young midfielder Alan Burton has joined non-league side Marine on a month's loan.
Stanley will be attempting to win a third successive game for the first time this season.
Source: PA
Source: PA