Those that know the 27-year-old defender off the pitch recognise plenty of his traits follow him over the white line. Barking orders, never shirking a tackle or a header and driving his team-mates on comes naturally to him. If you challenged him to game of simulated football on a games console you feel he may ask for 10 minutes to prepare and psyche himself up, such is his competitive nature.
However, when faced with the questions from a local press corps understandably asking questions about Argyle's recent poor form, Hartley gave an honest, calm and fair assessment of how the current situation feels within Home Park's walls.
"I think people outside of the club are more worried than people inside the club," said Peter. "Nothing’s changed; everything’s under control. We know exactly what we need to do. We had a really tough, sharp session this morning (Wednesday), we have another one tomorrow. Then we go to Morecambe and come back on Friday with three points.
"What’s happened, happened - you don’t look in the past, it’s gone now. People talk about it but it doesn’t really bother me; it doesn’t bother anyone in the dressing room; doesn’t bother any of the management staff.
"We are here, we are Plymouth Argyle, and we are going to go out there and try to win every single game. Not going away from home and trying to pick a point up. We know on our day we are the best team in this league. Whether we’ve been consistent enough is the question, but we’ve slipped up a few times we’ve conceded a few late goals, but that’s football.
Top teams do it, teams in League 2 100 percent are going to do it. But nothing’s changed mentally, everyone’s still in the right frame of mind to go and get the job done.
"I’m not even looking at the league, honestly I’m not. Everyone outside the club is worried about the fact that we dropped out of the top three. I couldn’t care less. We’ve got nine games left and 27 points to play for. If we win nine games, we’re in the top three and we get promoted. As long as we get promoted I don’t care where we are now."
As the previous text details, Hartley is not even shy of the oft-avoided 'p-word'. Promotion is the goal, and one of Argyle's trump cards in the tense and twisting run-in may be the amount of people in the dressing room with promotions to their name.
From Derek Adams - two with Ross County as a boss, at least - to coach Paul Wotton's pair of titles with Argyle as a captain and downwards throughout the playing staff, there are people with experience of promotion. Carl McHugh helped Bradford out of this league; Josh Simpson did it with Crawley; Kelvin Mellor was part of a Crewe side that escaped the division; Daniel Nardiello scored goals for Bury as they went up; and of course Luke McCormick was around for one Argyle promotion, then played a huge part in a second.
Hartley has one promotion on his CV, with first club Sunderland, but his minimal minutes in that campaign mean it would pale into comparison with a leading role in Argyle escaping League 2.
He said: "It’s good to have a promotion on your CV. I got a championship promotion with Sunderland, but I played a little part in that. As a pro who has played the majority of the games this season, I’d be disappointed if I didn’t get an automatic promotion on my CV. I’m literally doing everything I can 24/7 to succeed.
"Luke McCormick's been promoted twice with this club, so he knows what it takes. There are guys that know what it takes, and Luke's done it before. Curtis Nelson has been with the club through thick and thin. We’ve got a good solid base of five players that can shore up shop and let the front boys win us a game.
"I think we’re in a good position, everyone outside the club is worrying but there is no pressure on us at all. If anyone in this room had said to anyone that youre going to be fourth in the league in the same points as third with nine games to go, he’d snatch your hand off after what the club's been through."
Fifteen minutes in a presser with Pete and you feel so much more optimistic than when you walked in. He is that type of character - and he is not for changin.
"It’s just the way I am," he says. "I’m not going to change who I am, it’s the way I’ve been brought up. I fight for everything I’ve got and I’m not going to change now.
"All I want to do is get Plymouth Argyle into League 1."