Defender Shane Lowry - who started at left-back in the 1-0 defeat by Coventry last Saturday - has returned to parent club Aston Villa following his initial three-month loan spell with Argyle.
And right-back David Gray - who also started against Coventry - has returned to Manchester United at the end of his loan spell with Plymouth.
Argyle's on-loan Cardiff right-back Darcy Blake cannot play against his parent club, so Mariner will have to find a replacement.
Karl Duguid normally plays in central midfield but could fill in at right-back while Mariner is hoping experienced defender Chris Barker, ruled out since the start of the season by a calf injury, will be fit to vie with Gary Sawyer for the left-back berth.
Argyle are boosted by the return of midfielder Luke Summerfield at the end of his successful three-month loan spell at Leyton Orient, where he earned glowing praise.