"The bonus ball for us, when you look at the debris of a defeat and try to pick out some positives, was Calum MacRae," said Ruddock.
"He slotted into the No.10 slot without too much practice and didn't look out of place at all.
"Calum has been a really good signing for us and has great leadership qualities and is very experienced.
"He showed his versatility by going in at fly half and helping us score a couple of tries in the second half. He even kicked a couple of excellent conversions - that was great to see."
Ruddock made 11 changes for the clash in Wales and admitted the LV= Cup competition had allowed him to blood young prospects and also protect players with one eye on the Guinness Premiership.
"We had a great start last week against Newcastle and played a lot of our senior players like Pat Sanderson, Sam Tuitupou and Willie Walker," he added.
"But we have three massive Guinness Premiership games coming up, including Bath on Friday night with a six day turnaround for that.
"As much as I wanted to win at Scarlets our bread and butter is the Guinness Premiership and I don't want injuries and guys carrying knocks all week as we prepare for Bath.
"I had to make a call and we will only get stronger because we have blooded some of these youngsters.
"We had a lot of our own Academy products out there today, some will make it and go on to become regulars for us and perhaps some won't, but it's a great tournament.
"The intensity of the Guinness Premiership, with the play offs at the top, relegation at the bottom and 22 games of that magnitude, is huge.
"You can't put the same guys out every week so you have to mix it around. But we are hoping out of that defeat some of those guys will come through and be regulars for us.
"I thought we did well at the breakdown against Scarlets and turned a lot of their ball over.
"We have a lot of talented back row forwards who could go on and become big players for us, players like Jake Abbott, Matt Cox, who had a very good second half, and James Collins, who worked hard.
"If one of those guys comes through that will be a bonus for us and this type of competition allows us to mix up our selections to try and do that."