Michael Duff was disappointed with the nature of the goals his side conceded in their Emirates FA Cup exit at Accrington Stanley.
The Robins boss saw his side produce a good first half performance at the Wham Stadium against opposition a league higher, however the second 45 minutes cost his team who conceded three times.
Substitute Offrande Zanzala made a difference coming off the bench at the interval, scoring Accrington's first and winning a penalty for their second.
"He was the difference in the game, clearly," Duff said when asked about Zanzala's impact on the game. "I think if he had played for us in the first half he would have scored a couple of goals. That was the difference between the teams.
"The disappointing thing from our point of view is I thought we were excellent first half. We gave them a poor goal. We've done it twice this week. You can't go away from home against a good team, top of your division, or in a division higher and give them a goal like that.
"That's the problem with us at the minute. We've given two soft goals away and come under a little bit of pressure and don't seem to weather the storm well enough. We're good when we're good but when we come under a bit of pressure we seem to concede too easily at the minute."
The Robins return to action on Tuesday evening when Newport County are the visitors in the Checkatrade Trophy to the Jonny-Rocks Stadium.