The 27-year-old guard, a five-time NBA All-Star who spent five seasons with Utah before joining the Cavs in 2022, averaged 26.6 points and career highs of 6.1 assists, 5.1 rebounds and 1.8 steals a game last season.
NBA free agency rules place a moratorium on signings until Saturday, meaning teams cannot complete deals, leaving media reports to reveal what plans are in store for top players and clubs.
The Cavaliers, who lost to eventual champion Boston in the second round of last season's playoffs, fired coach J.B. Bickerstaff after the campaign and have hired former Golden State assistant coach Kenny Atkinson as their new head coach.
Donovan's deal, according to ESPN, includes a $54 million player option for the 2027-28 season, pushing the Cavs to become a contender in the next three seasons to keep the star playmaker.
Free agency has already produced some big moves, with Paul George departing the Los Angeles Clippers to join the Philadelphia 76ers and Klay Thompson leaving the Golden State Warriors to join Luka Doncic and Kyrie Irving with the Dallas Mavericks, who lost to Boston in last month's NBA Finals.
The Celtics have signed extensions with their starting lineup after making a deal Monday with Jayson Tatum for a five-year extension worth $315 million -- the largest contract in league history.
Among other free agents on the market is LeBron James, who is expected to make a deal to stay with the Los Angeles Lakers and play alongside his son Bronny, taken by the team in the second round of last week's NBA Draft.
