VIDEO: McCall reacts to Sarries' losing streak
Saracens, who were hammered by 32 points by Clermont in a weather-delayed game in France last Monday, saw their recent poor form continue with an agonising 21-24 loss in the second repeat of last year's European Final in less than a week.
The reigning European champions have now lost seven matches in a row in all competitions.
Smarting Saracens raced to a 13-0 lead with a try by Ben Spencer and a conversion and two penalties from Owen Farrell.
Morgan Parra responded with six straight penalties to put the home team five points ahead, but Farrell replied with three points of his own and Alex Lozowski scored an unconverted try to put Sarries back in front.
But in a chaotic and error-filled final 15 minutes, Parra and Scott Spedding each kicked a penalty to secure the victory which lifted the French club five points clear at the head of Pool Two and dropped Saracens to third.
McCall has said that his players were backing themselves to bounce back in the two remaining rounds to get into the play-offs.
They play Ospreys at the Liberty Stadium in mid-January and host winless Northampton Saints at Allianz Park a week later.
The Saracens Director of Rugby said that he is optimistic heading into the rest of the season and is confident the tide will turn.
"Everyone's saying that it felt good and felt better out there [against Clermont], but there's more to come," he said.
"Of course we can improve and have to if we want to win games like that; there's improvement in us for definite.
"We all know that we're going to get through this patch, whether it's next week in Leicester or the week after at Allianz Park against Worcester.
"We've got a good chance in the last two games to get ourselves into a qualifying position for the knockout phases of the Champions Cup, which is what we want.
"We want to get into the top four in the Premiership and have a chance of doing that as well, we'll get through this little period."
McCall praised his players' response to a tricky run of results, saying: "Just given where we were on Monday evening into Tuesday morning after the defeat and the manner of it at home and having to come here which is a pretty difficult place to come along.
"We also had added injuries to the existing list after Brad [Barritt] and Richard Wigglesworth were ruled out.
"We were written off by lots of people and to come and play the way we played, we attacked the game, competed for absolutely everything and fought for everything.
"We also played good rugby as well as defending much, much better so it just felt like we were much more like ourselves.
