Saracens director of rugby Mark McCall says his players need to "improve in all areas" if they are to beat Munster in their return Heineken Cup fixture on Sunday.

The Men in Black underperformed in the 15-9 defeat last weekend at Thomond Park but they have the chance to put things right in the return match at Vicarage Road on Sunday.

McCall admits his team were out of sorts against the Irish giants but insists the players can overturn the result this time around.

"I think we proably need to improve in all areas – we were well below our best last week," McCall told the Watford Observer.

"The players enjoy playing at Vicarage Road and hopefully there will be a good crowd there but we know the areas we need to improve to give a much better performance and if we can give a much better performance we have a good chance of winning the match.

"We set ourselves high standards as a team and in certain areas we felt that those standards fell short. We can rectify those areas and I think we’ll be better this week."

The Sarries boss refused to blame the defeat on the players' attitude or preparation although he admitted it was always going to be a difficult task beating Munster at Thomond Park.

"There was nothing wrong with our effort and our physicality - in the second half the team showed a lot of character and a whole lot of fight to ensure we came away with something from the match.

"Munster is a difficult place to go and when you think they have only lost three matches in something like 50 odd games down the years it was always going to be tough."

Saracens were able to call upon their international stars last weekend for the first time in over a month.

And McCall hopes that an extra week of being together and training together will enhance the team's performance. 

"Now that the international players are back in our system we’ve had a good training week and a longer training week than when we had a six day turnaround after Gloucester so I think we're in a much better position for this game," he said.

"It's not a case of fatigue. Having a number of players away for such a long period I think if you look back to the first ten games when the group were together it was at the back end of those games that we really started to find some very good form.

"The two European Cup games against Edinburgh and Racing were I think game seven and eight when we played really well and we backed those up with some hard wins away.

"Then you split up as a group for five weeks and it sometimes takes time just to get everybody back on track again and we've got to make sure that we're better than we were last week.

"It's not a reason for us losing, it's just inevitable that having not been together for five weeks we weren’t going to be as quite as spirited as we were before that five-week period."

Saracens' starting line-up will be announced today at 12 noon.