Mariner said: "You could see it in training. I said to (assistant) John (Carver) I think that's the best training session I've seen since I have been here.
"The players looked razor sharp. Obviously the thing we want is competition for places. We have spoken to all the lads and they understand football is about healthy competition and that's what we have got.
"You only get one opportunity to make a first impression and the first impression of the new lads - and I include David Stockdale in this - is very positive."
Stockdale recently joined on loan from Fulham and has played in Argyle's last two games.
Source: Team Talk
Source: Team Talk