And as well as offering a chance to create life-long memories in the capital, the mid-week match presents the perfect opportunity for the pair to prove they can make the step up to international level after they were overlooked for a Qantas Wallabies squad spot for the three-Test series.
''The pressure in this game is going to be like finals and Test matches,'' said Mogg, who produced a series of stunning individual displays in the early part of the southern hemisphere season.
''The hardest thing with starting the year so well, the expectation is to do that well every game. But teams learn who you are and how you play. It shows what type of player you have to be to find new areas you can attack or do different things to get your team on the front foot.
''If I can use this experience on Tuesday night and take that into the finals, I won't get such a shock in the (Super XV) play-offs. It's well noted that I lost my form… but I think I'm getting better and better and I feel like I'm close to where I was at the start of the year.''
While Mogg set the world alight in the opening rounds of the Super XV campaign, Toomua has been a steadying influence throughout the season so far.
Christian Lealiifano was being tipped as a starting No10 for the Qantas Wallabies in 2013 but Toomua's fine form has seen his club colleague employed at inside centre for the Brumbies.
The 23-year-old has finally stayed injury free after missing nearly all of last term with a knee problem and both he and the Brumbies hope to continue reaping the rewards of their patience when they look to end The Lions' unbeaten run at the Canberra Stadium.
''We know the history of the Lions and how close the Brumbies came to beating them in 2001. We're so excited for it… we're not going to hold back and we won't be in awe of them,' said Toomua, who believes he is a better attacking player now than he was at the start of the season.
''It's just about noticing opportunities and knowing my role: early in the year I probably felt my role was different. At times I felt like a ninth forward, but now it's a balance. Being tough in defence and creating opportunities for myself and others in attack.''