Tounkara scored a brace in what was his first full game since featuring for Oldham last season, but says he has plenty more to offer.
The former Sunderland forward, 22, had two loan spells at Boundary Park last season before joining Rovers on a short-term deal back in February.
"I feel much fitter day after day," he told the Bristol Evening Post. "I'm not far away from full fitness, but I am sure there is more to come from me.
"It was the first time I had played a full game in almost a year so it was very hard. I just tried to do my best to put my team on the right foot and I was quite happy with how I did.
"I was a little bit disappointed because I think I could have scored even more goals. You should always be disappointed when you miss a couple of chances because I'm here to score goals. I hope I have done enough to play in the next game, but it's up to the gaffer."