Well-sourced reports earlier this month had suggested that Everton would be prepared to let Niasse go if their £13m valuation of the player was met, with Crystal Palace — he came within minutes of joining the Eagles on transfer deadline day in August — West Bromwich Albion, and Brighton among the clubs said to be interested.
In the wake of his goalscoring heroics off the bench against West Brom themselves this past weekend, however, Allardyce says that the Senegalese striker will be a much-needed asset in his squad between now and the end of the season.
“No I can't let Niasse go, there's no danger of that," he said of the Blues' second-top goalscorer this season. “The hardest thing to come here in January is to come and play upfront.
"And there is no way we can let Oumar go. We've given Dominic [Calvert-Lewin] the weekend off because of the huge amount of games he's played the fatigue he's suffered so we said go and chill, rest and recharge your batteries and come back.
“We need those three between now and the end of the season."
Together with Director of Football, Steve Walsh, Allardyce has been able to land much-needed striking reinforcements this month in the form of Cenk Tosun who was signed from Besiktas.
The Turk will need time to settle in the Premier League, however, and it was he who made way for Niasse with 21 minutes left of Saturday's 1-1 draw with the Baggies.
Niasse scored within a minute of coming on, bringing his tally for the season in all competitions to seven, level with Calvert-Lewin behind Wayne Rooney who has 11.