The England star, 23, has been linked with Manchester United and Chelsea after establishing himself as one of the Premier League's best midfielders.
It is claimed the Hammers want at least £100million for their captain - but Pearce, who only recently left his role at the London Stadium, insists the club will not sell at any price before the 2022/23 campaign.
In a revealing discussion on talkSPORT, the former West Ham coach suggests Rice 'carries' the team on a regular basis - and ranks above United legend and ex-Nottingham Forest teammate Roy Keane in terms of talent.
Pearce also referenced Kalvin Phillips' move to Manchester City and Raheem Sterling's imminent transfer to Chelsea, insisting it would be a 'waste of time' for the Hammers to part with their star man.
Jack Wilshere recently told talkSPORT Man United 'need' Rice and when asked if that move was a possibility, Pearce said: "No. No chance. It's irrelevant [the size of the bid].
"If you're talking [Kalvin] Phillips going for £45m and [Raheem] Sterling going for £45m, what are West Ham going to do with £45m?
"It's a waste of time. An absolute waste of time.
"David [Moyes] has been adamant and the board have been adamant that Declan is going nowhere and David is going to build a team around him.
"He is so crucial. I have loved the last two years working with the kid. Watching him play, watching him flourish, captaining the team.
"He's integral for England now, really integral. You take him out of that midfield, as we saw in the Hungary game.
"All of a sudden, 4-0 defeat, we got a little bit exposed.
"There is not a chance he is leaving."
He added: "Man United want to build their team around him.
"Various other teams in this country want to build their team around him.
"If you're West Ham, he's come through the academy, he's a fantastic young player, keep your best!"
When asked whether Rice is a future England captain, Pearce said: "Without a doubt. Just keep maturing, keep doing what he's doing, add some goals to his game, 100 per cent.
"I was fortunate enough to play with Roy Keane at Nottingham Forest. He was an outstanding talent when he arrived.
"I think at the same age, and I'm rolling the clock back two years for Dec, I would say he is slightly ahead of Roy.
"Now, Roy went on to bigger things than Declan has achieved at this moment in time.
"Roy had a lion underneath the engine and a will to win. I'm not suggesting Declan hasn't and he won't grow into that.
"With Dec's stature, if he started to add goals to his game… he is so important to West Ham, sitting in front of the back three, but if they could free him up more, he would score goals as well."
He added: "Declan's ability, his recovering tackles are sensational. Players think they have room when he's five years away but he covers that ground with a burst.
"He is like a lion hunting down a wildebeast that's injured, he's a brilliant player and he'll be at West Ham next season."
Some have suggested Rice is overvalued by West Ham at £100m, including ex-Crystal Palace owner and talkSPORT host Simon Jordan.
However, having worked alongside the midfielder for two years, Pearce insists the hype around Rice is totally justified, given his importance to West Ham.
He said: "Sometimes if you're a fan of a club and you make statements about other players, you're not watching them for 90 minutes.
"There won't be too many West Ham fans that don't know Rice carries that team on a regular basis."