It didn't quite seem his place to be doing that, but he's learning, and that suits the line of defence in front of him just fine.
"The feedback from them is that's definitely what they want."
Manchester has edged Canterbury's Hamish McGregor out in their battle for the one Commonwealth Games job. His form has been impressive and with that comes confidence, both for the player and those who rely on his instructions and his ability to fulfil the last line of defence duties.
His debut came at the 2012 Champions Trophy in Melbourne. At 24 and with the semifinal tonight against India being his 44th cap, Manchester has plenty of learning to do but there are good signs.
He's physically smaller than most glovemen so while he's watched them, studied their movements, he's been wary of following their technique too closely. Where they fill out the goal, he's got more space to cover.
"So style of play wise, I've always been careful. Guys like [former New Zealand keeper] Paul Woolford, big guys, I'm careful about copying them. I do a lot of work with Paul and feel that has benefited me. I bounce ideas off him and with him coming from the position of having done that."
Older New Zealand hands, like captain Dean Couzins and Andy Hayward, have a theory about noisy goalkeepers.
They both cited the approach of another recent Black Sticks keeper, Kyle Pontifex.
"He was annoying as hell on the field because he was yabber, yabber, yabber," Hayward said. "But part of that showed he was very confident and it's good to see Devon like that as well."
Couzins likes the increasing desire he's seen within Manchester to be the dominant player at the back.
"You can see the confidence in him. It might be through calling, or circle positioning or setting up penalty corner defence."
Manchester is an example of hockey striking it lucky, purely by chance. He was lined up for rugby at intermediate school but was a couple of kilograms too heavy.
So hockey it was and he was sent to Auckland trials soon after, made the age group rep team and "just been at it since".
How much time does he spend reconnoitring upcoming opponents and their shot-making tendencies, particularly at penalty corners? Some, but "when you're on the field that can be a really dangerous thought running through your head.
"If you go top right and he goes bottom left you're kind of stuffed. Once they pull the ball out [at a penalty corner] I just watch the ball and react to what happens."
He produced outstanding form during the World Cup and was strong and decisive against England in the Black Sticks' clutch 2-1 win this week which smoothed their passage to the semifinals.
India are waiting tonight, but Manchester is confident.
"I think we are looking good for the semifinals. We need to take a step up," he said after New Zealand's 6-1 win.
Expect "Noisy" Manchester to be calling the shots as New Zealand strive to make tomorrow night's final, almost certainly against old rivals and world No 1 Australia.
