The contract has a team option on the second year, the source said.
The deal can't be officially announced until Friday but Robinson tweeted Sunday that he was headed back to Michigan, where he played collegiately for two seasons with the Wolverines.
Robinson, 24, was limited to 23 games for the Indiana Pacers last season after he suffered an injury to the medial and lateral ligaments in his left ankle during a Sept. 29 practice. He underwent surgery in October and didn't make his season debut until late February.
The 2017 NBA Slam Dunk champion, he blossomed into a solid contributor the previous season for Indiana when he averaged a career-high 6.1 points and 3.6 rebounds in 20 minutes per game. Robinson shot .392 from the 3-point line, converting 49 of his 125 attempts.
At the time of his injury last season, he was shooting .412 from 3-point range, making 14 of his 34 attempts.