Both teams are locked in a battle for the final playoff spot in Kingstone Press Championship One, and Hemel in particular recognise defeat without securing a bonus point will effectively end their season.
Conversely they are also aware that victory at the weekend, and the following Saturday away to Oxford RLFC, will definitely ensure their participation in the first round of the playoffs.
Sixth-placed Stags are a point behind Gloucestershire, with just two games remaining until the end of the Championship One season.
Stags coach Troy Perkins said: “It’s sudden death for us now, and I spoke to the players about that on Tuesday.
“If we lose a game, our season’s finished. If it’s this week, the week after, or in a few weeks’ time, if we get beat our season’s over.
“It starts this week against a team that’s in the same situation as us. It’s a mini Grand Final, but the good thing is that our destiny is in our own hands.”
James Howitt (hand) and Stephen Bannister (knee) both look set to be fit for the Stags, giving Perkins a major boost ahead of Sunday’s match.
Perkins said: “We’re pretty hard to beat at home, and Gloucestershire have never beaten us yet. That’s a positive. We’ve played them five times and got five wins, and we want that to continue.
“We’ve got to be pretty confident that we’ve got a team that can win this week, and make an impact in the play-offs.”
All Golds coach Steve McCormack is set to have half-backs Matt Bradley and Ben White available for a match that could secure Gloucestershire’s place in the top-five.
McCormack said: “If we win and make sure Hemel don’t get a bonus point, then we’re in the play-offs.”
Tickets are priced at just £9 for adults if booked in advance from the club, or £12 on the day, while concessionary prices are £4.50 if booked in advance and £6 on the day.