Rangers conceded an enormous 50 goals last season in the Scottish Premiership, the most out of the league's top six and Gerrard has gone about looking to plug the leak.
Indeed, the signings of Connor Goldson, Nikola Katic and Allan McGregor have gone a long way into Rangers keeping five clean sheets in Gerrard's opening eight matches - conceding only three and remaining unbeaten.
The Gers drew 0-0 on Thursday night against Maribor and 26-year-old Halliday was used as a left-back with Jon Flanagan suspended and Borna Barisic cup tied. Halliday believes Gerrard has plugged the leak, something which Murty failed to do.
"There has been a lot of improvement in this squad, but I think the biggest one is the resilience," Halliday said. "A lot of the credit goes to the gaffer and his coaching staff.
"This is a team that has not been together for a long period of time. That's why places like Marbella, the pre-season camp, are so important. You can fit six weeks worth of training into two and you get to know each other better.
"The biggest improvement from last season is resilience. We're a hard team to beat, with and without the ball. So proud of the boys."
It has been a near-perfect start for Gerrard, who watched on in Slovenia as Rangers defended calmly and confidently to nullify anything Maribor threw at them. Goldson, Katic and McGregor performed impeccably.
The latter made an excellent point-blank save before stopping a penalty in injury time, but Rangers had chances of their own. Jamie Murphy and Scott Arfield perhaps should have found the back of the net.
Another excellent performance from Alfredo Morelos sees everything beginning to click into place for Rangers, and they will need to be at their best as they face a difficult trip to Rugby Park on Sunday to face Kilmarnock.