Mark McCall insists he is surprised at how far Saracens and Exeter Chiefs have been able to pull away from the rest of the league due to the strength in depth in the Gallagher Premiership.

His side defeated Wasps 29-6 at Allianz Park to record their 15th straight Premiership win and move to the top of the table, two points clear of the Chiefs and 14 ahead of third-placed Gloucester.

It took Sarries almost an hour to score a try against the visitors, who defended well but were ultimately undone by a Jamie George try and a careless mistake by Elliot Daly - who was intercepted by Nick Isiekwe.

And although it brought up a 15th straight league win, McCall insists it has not been as easy as it looks.

"I am surprised because of how good the other teams are. It is obviously very pleasing to have the number of points that we've got," he said.

"Wasps defended superbly in the first half and we didn't quite get the ball we wanted in the final third.

"At half-time we challenged ourselves to be persistent and wear them down and I am really pleased with how we played.

"It has been a really encouraging last three weeks for us and we have used almost everybody in the squad."

McCall also confirmed that Liam Williams has a hamstring injury and after resting Owen Farrell, he said: "Everybody has an individual plan and in Owen's case it is not just the playing time that he has but the responsibility too.

"I thought it would be a good idea to get him ready for the week and fresh."

Alex Lozowski was a perfect seven from seven off the tee, with five penalties and two conversions in the win, while Daly bagged Wasps' only points with two penalties of his own.

Hooker George crossed for the first try midway through the second half after Saracens worked space in the corner, before the predatory Isiekwe punished Daly's slack pass.

Dai Young was left frustrated by the mistakes his side made and said that the effort and commitment shown by his players is only what he would expect.

"I can't doubt the effort and commitment shown by the lads but it is like patting the milkman on the back for delivering the milk - it is part and parcel of what I expect," he said.

"It is really frustrating when you see some basic errors - that doesn't allow us to play the rugby we want to play.

"There is only one way around it - you just have to keep working at it and eventually it will start to click.

"If you look at the game, as we absorb pressure you think we would come out the other end but we don't sustain anything enough to score a try."