Leicester have picked up only two points from their last 12 games since hammering Manchester United 5-3 back in September.
The midlands club have struggled to compete on their return to the top flight and are bottom of the table with only two victories from 17 games.
Tottenham are Leicester's next opponents at the King Power Stadium on Boxing Day and they face a trip to manager Nigel Pearson's former club Hull City two days later.
Hull sit second-bottom ahead of their Boxing Day clash at Sunderland and Walsh has pinpointed the encounter with Steve Bruce's side as a crucial game.
He told Perform: "It becomes a cup final [against Hull], it's a must-win game like most of the games.
"We are going to have to start getting something away from home and Hull does become a big game."
The pressure on Pearson has mounted as Leicester's miserable form has continued and Walsh believes a win at the KC Stadium would be extra special for the ex-Hull boss.
He added: "It's going to be one where he needs to put one over on his old club and that's easier said than done at the moment. As it stands you grant a wish from anywhere to get a result."
Former centre-back Walsh is under no illusions as to the task Leicester face as they attempt to avoid the drop, but he is confident they can avoid relegation.
Walsh added: "I've got to remain positive, like the club and the players have to. It's worrying don't get me wrong, but if they can play as they can and put those chances away then things can change.
"But it's a massive ask at the moment."
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