Mariner told BBC Spotlight: "The players in the dressing room are fighting tooth and nail to get out of this predicament."
Plymouth drew 1-1 with Swansea, following Saturday's win at Barnsley.
Mariner added: "You never know if you've turned the corner or not, but all that you can do is your best so you have to keep going."
The 56-year-old said that despite Plymouth's lowly league position, his players had shown great character to come from behind and take points in their previous two matches.
Last weekend we were 9 points from safety. Today that is only 5 points
Johnny-Glen
"As long as we've got such spirit then who knows what can happen when you've got those things going for you."
The next test for Mariner's men will be the visit of high-flying Leicester City to Home Park on Saturday.
"There's no easy game in this league, no matter who you're playing," said Mariner.
"It'll be a very, very difficult game but the players will be ready."
Source: BBC Sport
Source: BBC Sport