Japanese left-hander Shota Imanaga and the Chicago Cubs are working toward an agreement, a source told ESPN's Jesse Rogers on Tuesday.

Imanaga, 30, excelled during eight seasons with the Yokohama Bay Stars in the Nippon Professional Baseball Organization, going 74-55 with a 2.96 ERA and striking out 1,183 in 1,129 innings.

While his fastball averages only 92 mph, Imanaga generates a significant amount of carry on the pitch, leading to the gaudy strikeout numbers and general effectiveness not often seen in someone who stands 5-foot-10.

In 2023, Imanaga, recognizable for throwback-style high socks, posted a 2.80 ERA and had nearly an 8-1 strikeout-to-walk ratio, punching out 174 and walking just 24 in 148 innings. He throws a variety of pitches -- in addition to the fastball, he's got a splitter, a traditional slider, a sweeper, a curveball, a cutter and a straight changeup -- though he could lessen his arsenal as he transitions to a different ball in MLB as well as more frequent starts.

Imanaga would fit near the top of the Cubs' rotation behind ace Justin Steele. Jameson Taillon and Kyle Hendricks slot in next, with youngsters Jordan Wicks and Javier Assad in the mix at the back end.

Steele is under team control for several more years, while Taillon is on a long-term deal. Hendricks will be a free agent after the 2024 season.

Besides Wicks and Assad, the team is also banking on its farm system to keep churning out young pitchers, as highly touted prospects Cade Horton and Ben Brown could make their way to the big leagues next season.

The move would easily be the Cubs' largest of the winter, as they were only showing up on the transactions page via minor league signings, outside of backup catcher Brian Serven, whom they claimed via the waiver wire from the Colorado Rockies.

The discussions with Imanaga come just days before Chicago's annual winter fan convention, where the spotlight will be on new manager Craig Counsell.

Imanaga is seen as perhaps the best pitcher in the second tier of this free agent class, with countrymen Shohei Ohtani and Yoshinobu Yamamoto joining Blake Snell, Aaron Nola and Jordan Montgomery among the most sought-after arms.

Ohtani, the two-way star, agreed to a record-setting 10-year, $700 million contract with the Los Angeles Dodgers. Yamamoto set a record for a Japanese player coming to the United States, receiving $325 million from the Dodgers over 12 seasons.

Imanaga started the World Baseball Classic final for Team Japan and earned the win in the finals against the U.S., allowing one run over two innings while Team USA starter Merrill Kelly gave up a pair of runs in 1 innings. In six innings at the WBC, Imanaga allowed two runs on seven hits with no walks and seven strikeouts.

USA Today Sports first reported the progression in talks between Imanaga and the Cubs.

ESPN's Jeff Passan contributed to this report.