Dropping Trent Merrin was a difficult decision for St George Illawarra coach Paul McGregor, who has made good on a vow to value training performance over reputation.

The former Test and State of Origin forward was left out of the Dragons’ side to face the Warriors on Saturday along with Issac Luke and Tim Lafai, all of whom played the first two rounds of the NRL season.

McGregor said the return of skipper Cameron McInnes made it an easy decision to leave Luke out of the team to face his former club.

The ex-New Zealand hooker has also been battling illness, missing three of the last nine training sessions, but was cleared of the coronavirus after undergoing a test last week.

Merrin, however, was outdone by another forward at training and has been named on an extended bench.

“With Mez, a difficult one,” said McGregor on Thursday.

“He’s a person of great character, he’s a really liked team member.

“It came down to a decision that was between him and another player and the other player won the battle for round three.

“Mez knows what he needs to work on, he’s working hard at it and when he gets his opportunity it’s his spot to lose then.”

Lafai was hospitalised after an incident at his family home on Good Friday and missed a significant amount of training as he dealt with mental health issues.

However, McGregor confirmed he is on the right track to recovery and needs further contact and training to be in the right condition for NRL selection.

“Tim’s going good, he’s certainly on the right path to full recovery,” he said.

“He missed a lot of training, so although he’s healthy for selection he’s not hardened for selection.

“With the amount of training he’s missed he needs to do more work to be ready and I just thought (to pick) the other centres in front of him, due to that reason.

“But Tim’s getting the right help, he’s been training consistently over the last two weeks so he’s on a really good position in life to keep improving on a daily basis.”

Meanwhile, Zac Lomax has been moved into the centres in his preferred position, allowing Matt Dufty to resume at fullback.

Lomax played the first game of the season in the No.1 jersey, but McGregor said he’s not developing in the role as naturally as he would like.

“The development and improvement hasn’t come naturally enough to him yet, and the way Dufty has trained … in the scrimmage on the weekend he was the best player on the footy field,” McGregor said.