Pre-season is drawing to an end and for Derby County, it’s been a tough summer of building fitness back up for the campaign ahead. The latest test for Paul Warne and his squad was a trip to Oakwell, taking on League One outfit Barnsley on Wednesday night. A Nathaniel Mendez-Laing double was backed up by a comfortable James Collins goal to flex the Rams and their attacking side of the game. However, with four goals shipped the other way, there are clearly a few issues that need ironing out before the Championship gets underway. So with that said, here’s a look at some winners and losers from De…