Langfield was between the sticks as the Dons recorded a 2-1 win over Kilmarnock in last week's Scottish Premiership opener.
He is keen to retain his place for Sunday's visit to Motherwell but knows he faces stiff competition this term from Weaver, after the former Manchester City and Sheffield Wednesday keeper was recruited on a short-term deal in the summer.
Langfield said: "I've never seen myself as a number one here. In my eyes, there are two goalkeepers playing for the one position.
"It's up to me to train as hard as I possibly can and play to my full potential in games. Nicky is a great goalkeeper, a great guy as well, and I'm really enjoying working with him.
"If Nicky is performing well in training, it means I need to perform even better. Competition all over the pitch is what we need but I'm up for the challenge and always have been up for the challenge."
The Dons have been boosted by their positive start to the campaign but Langfield warned against reading too much into the result ahead of another tough clash with Motherwell.
He said: "It wasn't just the result, the performance was also a big plus for the manager. It showed how strong the boys are, how fit they are and showed they've had a really good pre-season.
"The icing on the cake was the three points but it's only one result. We are not going to get carried away. We've got a massive game against Motherwell on Sunday and we will go there in a confident mood."
Motherwell head into the match on the back of their Europa League qualifying exit to Kuban Krasnodar but Langfield does not expect their continental efforts to have any bearing on the meeting with the Dons.
He said: "They are professionals and they will always be up for the game. I don't think it's anything to do with the European campaign.
"They will be disappointed they have gone out but if you ask Stuart McCall and the Motherwell fans, their main focus is the league and the cups again this year. A game against Aberdeen is a difficult game for them as well so it has the makings of a great game."