Fellow keeper Brown kept 14 clean sheets in five months since replacing blunder-prone Langfield, but mistakes in key games against Dundee Utd and Celtic cost the English stopper his place.
Gaffer Derek McInnes handed Langfield a surprise recall in the Dons' match with Motherwell on Friday night, in a strange starting XI that left many Dons fans scratching their heads.
The 35-year-old was picking the ball out of the net after only half an hour of his return, but the Dons went on to win the encounter 2-1 thanks to goalkeeping howlers at the other end.
Langfield told RedTV: "Scotty has been great and we work really well together. He's a great guy off the pitch.
"I've sat back and watched him rack up clean sheet after clean sheet. You do think: 'Is my chance ever going to come?'
"However, I just needed to make sure I was ready. I kept myself fit and showed the desire that I wanted to be back playing.
"Thankfully it has paid off for me and the manager has seen something in me that has made him decide to put me back in.
"I feel for Scott because I'm close to him as a friend but at the same time I need to be selfish and think about myself. It could all change next week but hopefully if I keep doing what I'm doing, I'll keep giving the manager a headache."