Doncaster hadn't won in nine games and had scored only two goals during that time before their 3-0 demolition of the Latics on Saturday.
Rosler was quick to point out the effect that the brutal run of games has had on his squad and that he had feared such a performance was coming.
The Latics boss told the Wigan Evening Post: “Obviously we weren’t at our best. When you’re not at your best, you have to make sure you stay in the game.
“Their first goal came from an easy mistake, but we have enough good chances in that first half to have scored. We didn’t manage to do so, and in the second half I never felt we had the energy to come back into the game.
“We paid a heavy price for our gruelling schedule. We couldn’t go any more or put enough pressure on them. We looked leggy, and we couldn’t turn it around.
“To then concede the second and third...with the aspirations we have, that is just not good enough It came to a point in the game where we seemed to have given up, and that’s not like us nor is it acceptable when you see how many supporters have made the journey to support us.
“But I do understand what the players went through, and a game like this was going to come at some stage - it came today.
“It’s not about losing one game - it’s about how we bounce back from this and how we react. I’m looking forward to seeing the reaction from the players in the week.”
Nicky Maynard had made his debut for the Latics following his loan switch from Cardiff City whilst Tyias Browning started at full back.
Next up for the Latics is the visit of Crystal Palace in the FA Cup at the DW Stadium on Saturday. Tickets are priced at £10 for adults, £7 for concessions, and £5 for under 16's.