Pearson is under pressure with Leicester bottom of the Premier League following a dismal run in which they have taken just two points from their last 12 games.
The Midlands outfit have scored only 15 goals from their first 17 games back in the top flight and five of those came in September's win over Manchester United.
David Nugent and Jamie Vardy forged a prolific strike partnership in the Championship last season, but they have just one league goal apiece this term.
Leonardo Ulloa is top scorer with six goals and Walsh believes Pearson needs to bring in new faces to give Leicester a cutting edge, as well as acquiring new full-backs during the January transfer window.
When asked if Pearson needs to add new striker, Walsh told Perform: "He's got to, because they've simply had their chance and not done it.
"We are looking at a key area and also the full-backs have been giving silly errors away and quite blatantly these are the areas that Nigel will be looking to strengthen.
"We've got to tighten up and finish them chances, because you look at Burnley, the teams we should have beat, West Brom; I watched the games at home and we should have won, but we haven't.
"The stats say you are in that position for a reason and that's because you've not been putting your chances away and conceding bad goals."
Leicester host Tottenham on Boxing Day, then travel to fellow strugglers Hull City two days later.
