The diminutive Mosgiel midfielder steadily improved in his time with Otago United during the summer, and has made an explosive start to the FPL, scoring three goals in two matches.
Always a good technician, Day has become stronger on the ball, and so far his goals have been nothing less than spectacular, including a clever chip over Northern's advancing keeper, then a rare diving header to score again.
Mosgiel lost regular striker Shayne Danielson this year, and while Phil Kelly shows no signs of retiring, the side relies on a swarming wide attack using the pace of Regan Coldicott and Tim Dunn, while Luke Burgess leads up the middle.
The return of top keeper Peter Evans should steady a Roslyn defence that conceded 35 goals last year, six of them to Mosgiel.
While big centreback Davy Shaw's presence will be missed, Roslyn has already registered two clean sheets.
Tom Connor has also improved from his national league experience, and in Tim Mather, Mike Cunningham, James Watson and Brad Johnston, the potential is there to keep things tight at the back.
In attack, Roslyn has James Govan and Peter Rae to lead the line, and there is skill and purpose among Ajay Cunningham, Fraser Cameron, and the industrious Sam Mepham in midfield.
After stuttering a bit last week against a determined Grants Braes, Caversham needs solid improvement against Northern at Tonga Park.
Caversham could benefit from the return of Tom Schwarz from Canterbury, and coach Richard Murray will no doubt have cracked the whip in midweek training.
Northern showed character last week to fight back from three down to Mosgiel, and finished strongly, despite the 3-2 loss.
Licking wounds from last week's 11-0 mauling by Technical, Queenstown again makes the long journey from Central Otago, this time to play University at the Caledonian Ground.
Early away matches put pressure on player-coach Steve Henderson's team, and when last seen, goalkeeper Ian Rogers was limping badly.
University has a big, strong skilful side that coach Luke Macris feels is capable of challenging for honours.
He has a broad-based attack that earned goals for Dylan Stone, Tim Witten-Sage and Josh Groom last week, and the pattern should continue.
Lots of interest will focus on the Green Island versus Grants Braes match at Sunnyvale, where the two winless sides will aim to open their accounts.
Island coach Rodney Fleming will now know his side's strengths and two goals by youngster Jack Kirkwood last week is a bright sign.
Grants Braes was unlucky not to earn a point last week, so coach Allan Laidler will have targeted some reward this week.
Mike Fridge's Technical heads for Invercargill to tackle Spirit FC on its home turf, where the artificial surface should favour good football.
