Dragons prop Paul Vaughan.

St George Illawarra coach Paul McGregor has challenged his players to use their second-half performance against the Warriors as a springboard for the remainder of the season – but they may have to do so without injured prop Paul Vaughan.

The NSW State of Origin forward came from the field in the 11th minute of Saturday’s 18-12 loss to the Warriors after twisting his leg in a tackle by Adam Blair and Agnatius Paasi, and was on crutches with his foot in a moon boot after the match.

McGregor said Dragons medical staff were unable to determine the extent of the injury and he admitted that Vaughan was worried.   

“He is not sure whether it is his knee or his ankle,” McGregor said. “He heard something pop so he is just sort of in a bit of, I suppose, freeze mode at the moment.

“He is concerned, to be honest with you. We will have to wait until we get a scan and go from there but it doesn’t look promising at all, really.”

Besides losing Vaughan early in the match, the Dragons had to endure the costliest sin-binning of the season as the Warriors scored three tries in 10 minutes when Matt Dufty was banished for a professional foul.

“The sin-binning obviously at that stage didn’t help,” McGregor said. “[There were] six penalties against the opposition in the second half and no one goes to the bin, and four inside the 20-metre zone. But that’s not an excuse.”

The Dragons played with increased intensity in the second half and reduced the scoreline to 18-12 after quick tries to hooker Cameron McInnes and interchange forward Luciano Leilua.

Execution and poor ball control proved costly but McGregor liked what he saw, particularly in defence, and wants the team to build on their second-half effort heading into the Telstra Premiership finals.  

“Our second half was much better than our first and that is where it has to start next week,” McGregor said. “A zero scoreline for the opposition in the second half, we scored a couple of second-half tries, started to build pressure, our kicking game was better, we started to play through them a lot more, controlled their offloads better and made it a contest.

"Our completion rate was down on where it needs to be to be a top-four side and when we lost someone in the bin they capitalised on it. But I think that second half has got to be where we start next week – the way we defended with a bit of better execution, obviously."

McGregor conceded the attack had been too sideways and he noted that some of the St George Illawarra forwards appeared tired towards the back end of the first half.

“There was some hands on hips after about 20 or 25 minutes, not all players but some players,” McGregor said.

Asked about comparisons with past fadeouts by Dragons teams late in the season after their fourth loss in five matches, McGregor said: “It’s not going away until you win. Our vision is on what we want to do, not a revision. However, everyone is going to talk about because we lost.”