EXPERIENCED lock Donncha O’Callaghan has urged his Worcester Warriors’ team-mates to back up their remarkable victory against reigning Aviva Premiership champions Saracens.

The former Ireland and Munster star admits Warriors have “under-performed” in the league this term and must not let their 24-18 victory against Sarries just be a “one-off”.

Second-bottom Warriors face another stern test on Saturday when they host third-placed Exeter Chiefs (3pm).

Warriors have never beaten Chiefs in the top tier of English rugby.

Chiefs thumped Warriors 57-22 in November and drew 35-35 in an astonishing match with table-topping Wasps at Sandy Park last Sunday.

“I think Saracens under-performed last weekend and sometimes that’s what you need for things to go your way,” said O’Callaghan, who skippered Warriors to victory.

“If we’re honest, we’ve under-performed in the league.

“We have not put it in week in week out in terms of effort and we have to back it up and it’s down to the players.

“Some people might think Worcester have played their big final against Saracens and that’s enough of a scalp for the season but if that’s the case it would be massively disappointing.

“We to have rock up every day, try to be better and improve and look to get better in every match.

“We need to be up there every week because we are not good enough to play at 80 per cent.

“We need to be at those levels and play a bit beyond ourselves.

“If the victory and performance against Sarries are a one-off then it would shame on us.”

O’Callaghan was at his abrasive best in Warriors’ shock win against Sarries and felt the hosts played “really well” and “fronted up”.

The 37-year-old had been feeling sick “all week” after being told he would be leading Warriors into battle.

“It was a massive honour but I was so nervous that I felt sick all week as soon I heard the news,” said the Grand Slam winner and former British and Irish Lions ace.

“It’s a massive responsibility and you feel the pressure of it.

“There’s an unbelievable group of players at Worcester and you nearly have to ignite them with confidence.

“Some guys in our squad don’t know how good they are and how much they can achieve and some guys maybe tread water when they should push on. But I was really proud and it meant a lot."

The Cork-born second row has clicked with Worcester’s new director of rugby Gary Gold who has “been straight” with the players.

“Gary has been straight down the line and his values and the type of character he is sits easy with me,” said O’Callaghan.

“I am in no doubt about what he wants.

“I am a bit embarrassed we have to be coached on stuff like attitude because we have underperformed in that area.

“We have to get little margins right so we have to improve every day.

"Hopefully, we can be challenged and I think Gary’s a good man to do it.”

O’Callaghan is out of contract at the end of the term and is keen for Warriors to "push on" and "do better" in their remaining eight matches.

“The captaincy is not my call," he said.

"I am happy to do whatever the guys need out of me.

“When I signed for Warriors, I wanted us to push on and do better.

"If that means me being the skipper or the 24th man – I am happy to do it.”