For pop singer Lady Gaga, the album prize would be the first of her celebrated career. She has never won any of the top four Grammy prizes despite more than two decades in the music business. This year, she is competing with the album "Mayhem."
Grein predicted the trophy would go to Lamar, who won five Grammys a year ago for the single "Not Like Us."
Current events may boost support for Bad Bunny, Grein said.
The singer skipped the continental United States on his recent concert tour, saying he feared federal agents carrying out US President Donald Trump's immigration crackdown would show up to arrest his fans.
His selection for the coming Super Bowl halftime show on February 8 also drew objections from critics who argued the National Football League championship game's entertainment should be performed in English.
"I think the culture wars work in his favour," Grein said. "There are people who will vote for him in part - not only for this reason, but in part - as a rebuke to President Trump's anti-immigrant rhetoric."
Lamar and Gaga are represented by Universal Music Group (UMG.AS), opens new tab. Bad Bunny is signed by Puerto Rican label Rimas Entertainment.
Grammy winners will be chosen by the roughly 15,000 voting members of the Recording Academy — industry peers including artists, songwriters, producers and engineers — whose ranks have been revamped over the past seven years to increase diversity. About 1,000 Latin Grammys voters became eligible to vote this year, and 73% of members have joined since 2019.
Recording Academy Chief Executive Harvey Mason Jr. said the changes reflect the growing popularity of different types of music such as K-pop and Afrobeats, that now have fans around the world.
"For us, the academy, we had to keep up with that," he said. "We have to make sure we are responsible and we're honouring music regardless of where it comes from."
K-pop will be represented in the song of the year category, an honour for songwriters. "Golden," from Netflix (NFLX.O), opens new tab movie "KPop Demon Hunters," will face off with "APT.," a duet between KPop singer Rosé and Bruno Mars.
"APT." also will vie for record of the year, given to the performers and producers, against Lamar's "luther" collaboration with SZA and Gaga's "Abracadabra."
In the best new artist category, R&B and soul musician Leon Thomas is considered a frontrunner. He received six Grammy nominations in tota,l including an album of the year nod for "Mutt." His competitors include British soul-pop singer Olivia Dean and pop musician Alex Warren.
Scheduled performers include Sabrina Carpenter, Addison Rae and all eight best new artist nominees. Producers promised some surprise appearances among performers and presenters who have not been announced.
