The fourpiece was in Holland on tour when a friend contacted them with the "news".
"It turned out they'd just read the BBC's prediction list," 32-year-old Maclean laughs. "The person had to write back saying 'Sorry'".
If there's a moral to the story, it's read to the bottom of the page before you text. But the predictions proved accurate, at least in Django Django's case. Second time round, the news was fact.
"When we found out we were on the shortlist, the whole band was in the middle of some really petty argument, and the manager said: 'This'll cheer you up: you have been nominated'. And it did."
The Mercury nomination is for Django Django's self-titled debut album, which landed with a splash in late January, preceded by two singles, Waveforms and the insanely catchy Default. On the album, influences as varied as Link Wray and Giorgio Moroder are tossed into the Django Django mixer and blended into a 13-song suite which has attracted five-star reviews and appellations like "psychedelic" and "sunny" – or, as the NME phrased it, "Vitamin D-saturated".
If you turned on BBC Radio 6 Music any time in February and listened for more than 20 minutes, you would definitely have heard the band. They were everywhere. Accordingly, they're currently one of the favourites to scoop the £20,000 award on November 1, running neck-and-neck with rapper Plan B and Sheffield crooner Richard Hawley. The Yorkshireman probably deserves the win, but Django Django would be the people's choice.
"It's easy to say you don't care but I really don't mind not winning," says Maclean. "It's enough to have reached this stage and be nominated for an album that was essentially made as something that could be done quickly before we did what was – in our heads anyway – a proper album."
The band's roots lie at Edinburgh Art College, where Tayport-born Maclean and Edinburgh-born Tommy Grace met on the painting course. Another college friend was architecture student Vincent Neff, from Derry, now the band's frontman and, along with keyboard-player Grace, the main songwriter. The fourth member is Leeds-born Glasgow School of Art student Jimmy Dixon. He plays bass.
Maclean plays drums, though his real area of influence is in shaping the band's sound. What he calls "the musicality" comes from Neff and Grace. "Really I'm just channelling their stuff and putting the jigsaw pieces together," he says.
"I just sort of oversee things. But then I guess that's part of the job of the producer – I sit at the computer and take everybody's stuff and mess around with it. That's what I love to do."
That role is a legacy of his earlier incarnation as a dance-music DJ and sometime warm-up act for cult Scottish act The Beta Band, co-founded by his older brother John in the mid-1990s.
When the familial link between the two bands became clear, music critics weren't slow to point out the similarities in sound between them, though it isn't something that bothers Maclean. After all, he says, both he and John are products of the same environment – a family with a record collection rich in 1960s classics like Pink Floyd, The Beatles, Jimi Hendrix and Fleetwood Mac – so it stands to reason that there would be common ground born from their upbringing and shared musical interests.
"It would have been very difficult for me to sit down and say 'Let's try to make it sound unlike The Beta Band' because our sensibilities are so similar that it's just in my blood to be influenced by those [same] things – dub music, dance music. So we never really worried about it. We just got on with exactly what we wanted to do."
He admits, however, that The Beta Band was a large part of his life and that as well as absorbing his older brother's influences, he paid keen attention to the way he and his bandmates tried to navigate the music industry. It would turn out to be a perilous journey of thwarted talent.
"Through growing up with them and seeing their ups and downs, John's aware that I saw things going on and some mistakes being made," says Maclean. "But I don't think you can take anything away from their legacy. Overall they did everything right because they always stayed true to what they wanted to do. That's something that I've always thought was important – to follow your gut feeling and stick to your guns."
If the Scottish capital was the proving ground for the friendships on which the band is built, it was in the English capital that Django Django finally came together. Maclean moved to London five years ago to pursue a postgraduate degree at Chelsea Art College and was soon in contact with Neff and Grace, who had also travelled south after graduating. Pretty quickly the palette preoccupying him was of the sonic rather than the more traditional wooden variety.
"It was a bit like history repeating itself because I never went to college much first time round," he says matter-of-factly. "I guess I've always been distracted by other things."
For the Los Angeles Times, previewing last month's select few Californian dates, Django Django are an "East London band", the description being shorthand for "hip" and "cutting edge" and perfectly in keeping with the art-rock feel that pervades the band's music and videos. However, to those fans awaiting next week's homecoming dates at Glasgow's ABC and Edinburgh's Liquid Rooms, they're very definitely a Scottish group. How does Maclean see it?
"We feel like a Scottish band because half of the band is Scottish and we all met in Scotland," he says. "But then we feel like a London band because East London is our home now." It has, he adds, "been a really exciting place to be for the last five or six years", which might not be true of Edinburgh. That said, the capital show will be "a special gig".
"I was at the Liquid Rooms recently watching The Phantom Band, and I've been to so many gigs there and deejayed there so often over the years that it's a venue I know really well - But for me personally my homecoming gig this year was Dundee Doghouse. I still consider it my home city."
Mercury win or no Mercury win, work on the "proper" album Maclean alluded to begins in February, after the band return from a winter tour of Australia and before they depart for a series of spring dates in the US. It will probably take place in a remote part of Scotland – Maclean says he wants to instil a sense of "cabin fever" in his bandmates – though as yet he's unsure of whether it will be a "live" album, to reflect their increasing tightness as a band, or a stripped-back affair with "minimal" beats and minimalist songs. "I can see it going either way," he says. One thing is certain: it will be different.
"I think the first album was a collection of songs that were inspired right from the 1950s to now, because there was a lot of stuff in there we had to get out of our systems. When we were producing it I think my head was really with Joe Meek and Phil Spector and that sound. But I'd quite like to push this one forward from that."
So we've had sunny – or, if you prefer, Vitamin D-saturated. How, then, does the weather look for Django Django's next offering? Is there an east-coast haar on the horizon? Maclean laughs.
"I think we're too happy with our lives to be bothered about being miserable," he says. "Making music is what I absolutely love to do - I'm certainly not bored or cynical about it. I have a million ideas at the moment and I'm raring to go."
Come February and time for the studio, he adds: "I'm going to be like a kid in a sweetie shop."
Django Django play Edinburgh's Liquid Room on October 24 and Glasgow's ABC on October 25.