The Latics boss has already added Nicky Maynard and Tyias Browning to the side in his first transfer window with the club, while Grant Holt has joined Aston Villa on loan.
Rosler has not finished his shopping yet, but does not want to leave things to the last minute.
He told Wigan's official website: "I'm hoping to add a couple of players before the end of the transfer window, but I would prefer to do any business sooner rather than later."
Rosler understands that new signings need time to bed in at the club, citing Cardiff loanee Maynard as an example.
"I said before he walked in that we have to give him time, I gave him the chance at the weekend (in the defeat to Doncaster) because he was training really well," Rosler said.
"It's just a matter of time before he shows the consistency that we see on the training ground in match situations and over big periods of the game.
"His movement is first class and as a team we have to provide him with better service.
"Normally we do provide that service, but against Doncaster I would say that it was a one off."
Rosler also confirmed that midfielder Shaun Maloney has gone to the United States for a check up as he continues his recovery from hip surgery, but does not know when the Scotland international will be back available for selection.