Former Widnes Vikings half-back Gilmore has 41 Super League appearances to his name, including two on loan for Salford Red Devils last term, while Butterworth played twice in the top-flight for Huddersfield Giants during 2020.
Both caught the eye when Greenwood’s Dewsbury Rams won 22-20 at Batley Bulldogs, coached by Lingard, in the sides’ opening pre-season game last weekend.
Gilmore played for the opening 40 minutes as Bulldogs built a 14-10 interval lead and Lingard said: “I had a joke with him afterwards - he was a bit disappointed he didn’t play downhill in the second half.
“He only played 40 minutes and it was all uphill, but I think you could see his value when he was on the field.
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“We were certainly a better team when he was out there, a lot more organised.
“In the second half the younger, inexperienced players came on and we lost a little bit of control at times.
“You get that with young, inexperienced people, but if you don’t give them the game time they aren’t going to develop that knowhow.
“But certainly moving forward, it is imperative we get Tom Gilmore out on the field as much as we can.”
Butterworth, a hooker, began his career at Bradford Bulls and has also had loan spells with Batley and York City Knights.
Greenwood said: “He is a good player, similar to Dom [Speakman], who we’ve lost.
“He was good, we tried keeping the majority of our players on for 40 minutes, so he did 40 straight - and at a high level.
“He looked good defensively, but also with ball in hand.
“He will be a good signing for us and he complements Sam [Day], who did the second 40.”
Rams also gave a run out to trialist Alex Smith.
Greenwood said: “He has trained in pre-season with us he has come to our awareness from student rugby, but I think he did play one or two games for Salford reserves.
“He has impressed over pre-season and deserved to get a game.
“I thought he showed some nice touches out there.
“We have got half-backs that are 50 years old so [veterans Paul Sykes and Liam Finn] we do need to start looking at back-up there and people who can fill in for them.
“They can’t go on forever, though people have probably been saying that about them for the last 10 years.
“We do need people to step in - I thought Jamie Abram showed quick feet on a couple of occasions and broke up field in the first half and Alex showed some good touches and popped up in a few different areas.
“Hopefully they can show that again.”