The Magpies will put the finishing touches to their preparations for Monday's game at St James' Park already four points adrift of safety and knowing they could find themselves even worse off after the weekend fixtures.
Shearer is well aware the stakes could not be higher and is placing all his hope in successive home victories over Pompey, Middlesbrough and Fulham if the club is to avoid the drop.
Shearer: "I am hoping it is going to be a really special atmosphere.
"I want the fans to turn up in their thousands, really get behind us from the first minute and stick with us for the three remaining games.
"Hopefully, we can give them something to shout about. I know we are always asking something of our fans, but for three games more this season, I am asking for a little bit more from them."