The Leeds boss spoke to reporters after his side's 1-1 draw with Burnley.
Indeed, a satisfied Rosler was full of praise for the Yorkshire side after they more than matched Burnley at Elland Road on Saturday afternoon.
Leeds drew 1-1 with the Clarets in the end, having thought they had decided the match through Mirco Antenucci's second-half goal.
And Rosler says there is one important issue the Whites still need to work on in terms of their back line.
Asked whether he thought a couple of people might struggle in terms of their fitness, he told BBC Radio Leeds: "I think Chris Wood didn't struggle, Tom Adeyemi didn't struggle.
"I think we dropped a little bit in the back four. That is the issue we have to still work on. It's early days, we only had six weeks."
The Yorkshire side face Doncaster Rovers and Reading in the Capital One Cup then Championship respectively in the coming week and Rosler will no doubt look for a steady improvement game by game at Leeds.
This was certainly a strong start to their league campaign, as United looked equal to a side who went toe-to-toe with Premier League giants last season. A few more tweaks and Leeds fans can certainly anticipate their first win soon.