BOSTON (CBS) — The Celtics head into the home stretch of the regular season brimming with confidence, thanks to their shocking upset of the Golden State Warriors last Friday.

It was a much-needed confidence boost for a Celtics team that let one slip away the night before in Portland, Yahoo! Sports’ Chris Mannix told 98.5 The Sports Hub’s Zolak & Bertrand, setting them up nicely for their final five games of the regular season.

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“They needed it. You can’t lose a game like they did to Portland, get blown out by Golden State and have any confidence ending that road trip,” said Mannix. “There are too many key matchups in the next two weeks with Charlotte and Atlanta to not be brimming — or close to brimming — with confidence heading back to your home floor.”

While not much has changed on their roster from last season, when Boston won 40 games and was swept by the Cavaliers in the first round of the playoffs, Mannix says just about everyone on the team has become a better player. There’s one man Celtics fans can thank for that: head coach Brad Stevens.

“I don’t know if there’s a difference in how these guys think or operate but almost everyone on that team has taken some kind of step forward, and that’s a credit to Brad Stevens and what he’s done with these guys. Who knew who Jae Crowder was when he was in Dallas? Every year, Jae Crowder has gotten better. Ask scouts and they’ll he’s the most valuable Celtic for what he does on both ends,” said Mannix. “Isaiah gets better. Evan Turner gets more comfortable in that sixth man role.

“If it wasn’t for Marcus [Smart’s] errant shooting I’d say everyone has gotten better to this point, but they’re all taking steps forward to varying degrees and that’s why they are where they are.”

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Mannix said Stevens gets his vote for Coach of the Year.

“If this team finishes No. 3 in the Eastern Conference this year, and I think they can based on the schedule remaining, I would give Brad my vote in a close one over [Portland’s] Terry Stotts,” he said.

And if you’re concerned about the Celtics’ inability to play well against bigger teams in the league, Mannix says not to fret too much as we head into the postseason.

“The saving grace is there aren’t really many teams with great size and few in the East playoff mix,” he said. “Cleveland is now playing small, Toronto puts Jonas Valaciunas on the bench in key moments. Look at a first-round matchup with Miami; we don’t know what will happen with Bosh but Amar’e Stoudemire is getting minutes there. If size is a problem for Boston, they aren’t going to face much in the postseason.”

Mannix also touched on Terry Rozier’s play of late, the draft stock of Oklahoma star Buddy Hield and Monday night’s amazing NCAA title game:

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