Saracens boss Mark McCall feels "there is more" in his team after they made it 22 games unbeaten with a Heineken Cup Champions Cup victory over Cardiff Blues.

It was an often close-run contest at the Arms Park as Saracens' long run without defeat came under serious threat for large parts of the game.

England fly-half Owen Farrell's second-half penalty double and a Jamie George try saw them home 26-14 they strengthened their grip on Pool Three.

Farrell claimed afterwards that Saracens were "too nice" in the first half, and rugby director McCall did not disagree.

"I know what he (Farrell) means," McCall said. "We started well, but we kind of lost control of that first half by doing everything just okay.

"Our line speed that we wanted, there was a bit of a contrast between the first 20 minutes of the first half and second 20 minutes.

"We've got a group that is very picky with incredibly high standards. They are very ambitious.

"Today was about the result and getting it done, but overall there is a discontent with some of what we are serving up. There is more in us."

Farrell, meanwhile, told BT Sport: "The first half, we were too nice. We were just okay, and that's not what we are about.

"Cardiff have been a tough team these past two weeks, and credit to them, but we will be frustrated today for not putting a complete performance together.

"We are not saying it's not tough to come here to win - they are a top, top team - but in terms of how we've performed, the first half wasn't good enough."

Saracens wing Sean Maitland scored a first-half try, with Farrell kicking 16 points, while the Blues claimed touchdowns from centre Rey Lee-Lo and full-back Dan Fish.

Fly-half Gareth Anscombe kicked both conversions, yet the Blues are facing a pool-stage exit despite pushing Saracens hard just six days after suffering a 51-25 defeat against the same opponents at Allianz Park.

Saracens will secure their place in the last-eight if they beat struggling Lyon in France next month, with that game being followed by a home encounter against Glasgow.

McCall added: "There are aspects of our performance we would like to get better at.

"But when it came to it and when it really mattered when we were down to 14 men with 20 minutes to go, I thought we showed all of our experience and managed that part of the game superbly well. We were very composed."

The Blues could not capitalise on Saracens lock Will Skelton's spell in the sin-bin, although they gave Saracens far more to think about than during last weekend's 51-25 defeat at Allianz Park.

Blues head coach John Mulvihill said: "It was two tries-all against a team who normally concede only one try in the Premiership.

"We are in a competition with the 20 best teams in Europe, and out of the budgets we are ranked 20th.

"There is no point worrying about it because we know about the situation. When they have internationals on their bench, it makes their second half performance pretty good.

"We are growing our depth, but it is going to take a bit of time."