Cubelli rushed in for Brumbies start
The Brumbies play the Waratahs in Wagga Wagga on Saturday.
Cubelli joined the Brumbies at the end of 2015 from Belgrano Athletic Club in Argentina.
During his seven years with Belgrano, Cubelli was selected to play for Argentina, making 45 appearances for the national side since 2010, most notably in the 2015 World Cup.
After linking with the Brumbies in January, Cubelli has gone from strength to strength.
The Brumbies will be taking on the Waratahs in their first fixture of 2016 in Wagga Wagga on Saturday, with Cubelli named to make his first start.
Cubelli said he was looking forward to his first game in Brumbies colours.
"I'm really excited," the 26-year old said.
"I know that Waratahs and Brumbies is always a big game, so I know it's going to be a hard game.
"We have been working very hard and we really want to go on to the field and show what we have been doing in practice.
"I think the team is working well and now is the time to apply these things on the field."
Stepping into the scrumhalf role, the Los Pumas star knows he will need to stamp his authority early.
"It's an important role, the scrumhalf of the team," Cubelli said.
"The boys are making it quite easy for me so I have to be thankful for that. They are very understanding of my role and job, as well as my English – they are doing very well," Cubelli joked.
Starting alongside Cubelli at flyhalf will be Wallabies playmaker Matt Toomua, who went head-to-head with Cubelli in the Rugby World Cup semifinals.
Cubelli said he was excited to play alongside the talented flyhalf.
"We've been training a lot together, he's a great player and he makes things easy," Cubelli said.
"He's very good with me, he explains the plays and it explains what he wants. I'm very thankful for Matt and it will be a pleasure to play with him."
Cubelli said he was feeling very much at home in Canberra.
"I'm feeling really comfortable, I've settled in." Cubelli said.
"I'm working hard, running a lot and now I want to go on the field and have fun. It's been three weeks of hard work and now we want to take advantage of that."
Brumbies: 15 Aidan Toua, 14 Lausii Taliauli, 13 Andrew Smith, 12 Jordan Jackson-Hope, 11 Nigel Ah Wong, 10 Matt Toomua, 9 Tomás Cubelli, 8 Ita Vaea, 7 Jarrad Butler, 6 Jordan Smiler, 5 Sam Carter, 4 Tom Staniforth, 3 Ben Alexander, 2 Josh Mann-Rea, 1 Allan Alaalatoa.
Replacements – from: Albert Anae, Robbie Abel, Leslie Leuluai'ali'i-Makin, Ruan Smith, Rory Arnold, Blake Enever, Ben Hyne, Michael Wells, Joe Powell, Michael Dowsett, Nick Jooste, Joe Tomane, Jake Rakic, Tevita Kuridrani, James Dargaville, Isaac Thompson.
Date: Saturday, February 6
Venue: McDonald's Park, Wagga Wagga
Kick-off: 19.00 (08.00 GMT)
Referee: Will Houston/Nic Berry
Assistant referees: Angus Gardner, Will Houston/Nic Berry