Head Coach Gabriele Cioffi felt Reds deserved to come back from Carlisle with at least a point.
Instead they were condemned to a 2-1 loss, only their second opening-day defeat in nine years, despite a goal from Bez Lubala on his debut.
Gaby said: "They are a lot of positives, I think the boys put in a good performance.
"Our DNA was there in the way we played and competed, and at the end of the day it’s a matter of centimetres between us getting a good result or not and that is something we cannot control.
"But yes we have to be ruthless, we had a chance in the opening minutes which (Panutche) has to take and there were others.
"Their goalkeeper was man of the match and made two or three brilliant saves. I felt we were on top for large parts of the first half and most of the second half. I thought everyone performed, I’m struggling to thinking of someone who was the best. It was a performance of heart and football ideas from the team."
Gaby explained why he took off Dannie Bulman at the break on the midfielder's 400th appearance.
"We changed the team setting at half-time to try and be brave and win the game and I thought we controlled the second half," he added. "Dannie was playing well but I thought we had to get more on the front foot."
Gaby admitted he didn't see the stoppage-time incident which saw Lewis Young sent off for violent conduct. It means the defender will miss our next three games.
Reds return to The People's Pension Stadium on Saturday to take on Salford City.