IndyCar rookie McLaughlin has made a steady introduction to the American open wheel series and is 13th after a good result last time out at St Louis.
F2 racer Armstrong has had an up-and-down season and the Ferrari Academy driver is looking forward to what is in effect his home race, having spent the past five years based in Italy.
"We've had a few good moments through the season but not as many as I would have liked," Armstrong told the Weekend Herald from the DAMS factory in Italy.
"We came into the season with such high expectations. We had a few good races like Monaco, where I pulled off a good overtake, which is hard to do there, and we stood on the podium at Silverstone.
"We have a lot to do in the next four race weekends because we deserve better than this so far.
"Having such an up and down season is part of the sport, especially when you have three races on a weekend. You can have one good race, one bad race, then maybe another good one and it's just an emotional rollercoaster for everyone in the team," said Armstrong.
"That might be the case but it's not complicated. Although there are a lot of things to get right and a lot of variables in Formula 2, the team is good and we have the right package.
"The car is in a good place and it's just a matter of doing everything we can and I'm sure the results will come."
Monza is a track the Kiwi likes and is near the academy, and Armstrong has plenty of experience at the iconic circuit.
"The Italian fans are insane and will have been camping outside the track for days. It's such a cool environment to be racing in. I've done a lot of laps there — probably as many laps at Monza as I did at the Christchurch Kart Club," said Armstrong.
"Having raced with an Italian team for a number of years, we always did testing there, so I know it well. A lot of people say they don't enjoy Monza, but I do. The corners are quite satisfying.
"At Monza, the corners have different trajectories and it's pretty high speed, so when you get it right, it's really satisfying. The tarmac is good and you have more grip than you expect especially, after the Formula One cars have been on it.
"It's going to be really exciting because everyone I work with will be at the race. I have nothing to lose and they will all be there to support me. I'll be putting more pressure on myself than anyone else."