Cubs made 'best' free-agent deal of the winter, but it's not all sunshine and roses

The early returns from Shota Imanaga have not only exceeded even the loftiest expectations but have put him in some historic company one month into his MLB career. Executives across the league have taken notice and, in a recent MLB.com poll, tabbed him as the best free agent deal of the offseason by a wide margin.

The Chicago Cubs left-hander received 9 votes, more than double the runner-up, early NL MVP front-runner Shohei Ohtani. The two Japanese standouts were the only players to receive multiple votes in the poll, which included two dozen executives throughout the game.

“The strike-throwing and stuff quality have been strengths to stabilize an unsettled rotation,” an AL executive said. “A number of teams are probably thinking ‘what if?’ right now.”

According to Baseball Reference, Imanaga has been worth 1.8 bWAR in the season's first month and by Fangraphs' measures, 1.2 fWAR. He helped stabilize a Cubs rotation that lost its ace on Opening Night and didn't get Jameson Taillon until mid-April. His efforts earned him National League Rookie of the Year honors and has him as an early Rookie of the Year favorite, as well.

Cubs know Shota Imanaga can't keep this up forever, but still have faith in what he brings to the table every five days

But these same executives that showered him with his praise also expressed some concern about regression, a fair assessment given his otherwordly start to the year. Nobody is expecting him to maintain this level of dominance over the course of an entire season, but the general belief is that his floor is still high enough to make this a very sound deal.

“This level of performance isn’t sustainable,” an AL executive said. “But it looks like Imanaga is at least a [3-WAR] pitcher in the near-term and the cost wasn’t extreme.”

The Cubs' internal assessments of Imanaga looked wildly different than that of many other teams and, to this point, their faith has been rewarded in the form of one of the most dominant arms in the league. But the early returns paint a picture of an intelligent pitcher, capable of going toe-to-toe with anybody out there. From here, it's about making adjustments as the league starts changing its approach against him now that they've seen him.