Praise for 'professional' Sarries
The defending champions hammered their domestic rivals 50-3 to make it three wins from three matches in Europe this season.
Saracens are now in firm control of Pool Three ahead of next weekend's return clash with Sale at the AJ Bell Stadium.
And McCall was delighted with the way his men went about their business.
He said: "Because of the conditions it was hugely important that we did the fundamental things really well.
"Our set piece was going to be important, the penalty count was going to be important and I thought we were really professional in tough conditions. Our maul was good, our scrum as good. We defended well and after a spell in the first 15 minutes where we gave away three penalties we didn't give a penalties away for a long time."
Marcelo Bosch and Sean Maitland crossed to send the champions in at half-time with a 23-point lead before scores from Jamie George and Chris Wyles secured the try bonus point. Owen Farrell added 13 points from the boot before being given a well-earned rest at half-time.
The England playmaker leads the points-scoring charts with 48 from three rounds of European action. And McCall heaped praise on his leading man.
He said: "He's one of those players who leads in every way because he leads from the front. Some of his defending in the second quarter was out of this world. He leads through his actions, but also through his messages and communication with the team."
England hooker George continued his fine run of form with a try, and McCall believes he could soon be the occupant of the England No.2 shirt.
He added: "Jamie George has been playing well for a long time. Everybody knows it will happen sooner rather than later."
Source: @ChampionsCup