The 26-year-old Scotland striker claimed just his third goal of the season to inspire a late fightback at Cardiff on Saturday evening as Poyet's side claimed a 2-2 draw to go with their Boxing Day victory at Everton and boost their hopes of escaping the drop from the Barclays Premier League.
Speculation has suggested that Fletcher, a £12m signing from Wolves during the summer of 2012, could be a target for potential purchasers when the winter transfer window opens tomorrow, but Poyet is planning to have him at the pinnacle of his team.
"There are positions on the pitch, with respect to everybody, of course, and every single player, that are key in any team. People talk about the spine of the team - goalkeeper, centre-half, centre-midfielder and striker - but nowadays, I would like to say that everybody is looking for that striker who will score you 20 goals, so the strikers are the main ones.
"That's why sometimes they earn the most and they are most expensive ones to buy. Fletch is key, he is a key player for us and we need to make sure that we give him more chances.
"He had one only against Everton and he couldn't score, but then he had one and somehow I don't know how, still, he stretched himself to score the goal - so we need to put him in there many, many times so that he will score plenty of goals."
Poyet's favoured system includes just one frontman, and Fletcher and the United States internationalist Jozy Altidore have tended to alternate with their appearances together to date having yielded limited results.
But with the threat of relegation a very real one, the club are currently two points from safety, the Uruguayan admits he needs to design his team to get the best out of the Scot. He said: "I need to find the balance for him to have chances, yes."