The West Yorkshire club signed Sam Williams from Canberra Raiders in the winter on a 12-month deal and the Australian has impressed in his debut campaign at Belle Vue. Ireland captain Liam Finn has also proved an astute capture since joining from Castleford Tigers at the end of 2015, slotting in at hooker at times this term. He turns 34 in September but Wakefield have already turned down an approach from Dewsbury Rams for him to be their player-coach and Chester is keen to retain him. Likewise, Australian Jacob Miller, who played his 100th match in the British game in Easter Monday’s 16-10 loss to champions Wigan Warriors, is off-contract. He arrived from Hull FC ahead of the 2015 campaign and Chester said: “We’re in discussions with them all. “We’re a little bit further down the line with Liam. But with Sam and ‘Milky’ (Miller) they are two halves we want to keep hold of and want to tie down to some long-term deals. “But we’ll wait and see. I think both their agents are coming down for Magic Weekend so we get to sit down face to face which is a bit better than doing it over the phone.” Williams missed his first game of the season against Wigan after being rested following the Good Friday loss at leaders Castleford. But he returns at Warrington with Chester set to make a series of changes. Australian prop Mitch Allgood is out for six weeks after breaking his hand against Wigan, Matty Ashurst is missing with a slight calf problem and Dean Handley (triceps) is also a doubt. Chester explained: “Mitch broke his hand in two places in the second half but being the guy he is he ended up staying on and playing the rest of the game. He needs an operation and a plate put in there. “He missed the start of the season, too, so it is tough on him. I spoke to him last night. “A similar thing happened two years ago when I coached him at Hull KR. “Exactly the same game – Easter Monday – and we played Cas at Cas. “We lost him for four months but thankfully we only lose him for six weeks this time.” Chester added: “He’s been playing well, Mitch. We’ll miss him but it gives an opportunity to the rest of the squad. “Keegan Hirst will probably get some extended game-time as well and we’ll probably bring Jordan Crowther and Mickey Sio back into the 19 for Saturday.” Chester may also rest Scott Grix, the full-back who turns 33 next month but has been in fine form since joining from Huddersfield Giants in the winter. Highly-regarded youngster Max Jowitt is yet to play for Trinity this season due to Grix’s form. Chester said: “Max has been very professional. “He’s learned a lot from Grixy and had a few games out on dual reg. He’s obviously been disappointed but, when Grixy is playing so well, it’s difficult not to play him every week. “Hopefully if he gets an opportunity this week, he’ll take it with both hands. “I’ll try to rotate this week because this is generally the game that catches you out over Easter from a fatigue point of view so it’s important we bring some fresh guys into the squad. “Grixy has played every minute of every game and he’s not getting any younger. We’ve got to manage him over the next few weeks but we’ll decide on Friday the make-up of our team. “I was going to rest him on Monday but he was adamant that he wanted to play and put a few wrongs right from the game at Castleford.”