Reuben Reid headed home Conor Hourihane's 82nd-minute free-kick to ensure Rovers tasted derby defeat for the second time in four days following their midweek reverse at Bristol City.
"It was frustrating," Ward said. "Even at half-time I said to the boys 'I hope we have not lost the opportunity to win the game'.
"We fizzled out in the top third of the pitch and we haven't worked their 'keeper enough times for me to sit here and claim we could get a draw.
"At this moment in time there are not enough goals in my team and we need to work hard to improve in that part of the pitch.
"They have won the game and I am fine with that and I am not making any excuses and I want to stress that. I am not shouting and screaming but I still expect a bit more from the team in the top half of the pitch.
"We were a bit naive in some of our play, it was a little bit of hopeful football rather than building with a bit of a base so we have got to try and improve on that as well.
"We have given away five or six free-kicks in that area, hoped we'd clear it and on the one occasion we didn't we have lost the game."