Chicago Cubs left-hander Shota Imanaga is making the adjustment to the major leagues look easy.

Imanaga has yet to allow an earned run in his first 15 1/3 innings, a streak he will attempt to keep alive in Game 2 of Chicago’s day-night doubleheader against the visiting Miami Marlins on Saturday.

Chicago has won five of its past six games, while Miami has lost four out of five.

A two-time Nippon Professional Baseball All-Star in Japan, Imanaga (2-0, 0.00 ERA) signed a four-year, $53 million contract with the Cubs in January, and so far, he’s been worth every penny.

In his most recent outing, Imanaga came away with a win against the Seattle Mariners on April 13, when he gave up one unearned run on five hits in 5 1/3 innings.

Since earned runs became a statistic in 1913, no pitcher in Chicago franchise history had ever started a career without yielding an earned run through three straight appearances each lasting at least four innings.

Imanaga went six innings against the Colorado Rockies and four against the Los Angeles Dodgers in his first two starts.

“Shota’s incredible,” Cubs reliever Mark Leiter Jr. said. “The way he handles himself, the type of person he is, it’s all been great. And then, obviously, the pitcher that he is has really been a joy to watch.”

Before Imanaga takes the hill on Saturday, Chicago will turn to right-hander Javier Assad (2-0, 2.16 ERA) for the opener of the twin bill.

Assad’s latest start was also against Seattle, and he came away with a victory after allowing two runs on four hits in 5 2/3 innings on Sunday. Assad has never faced Miami in his career.

Going up against a pair of pitchers with sub-2.20 ERAs could pose a challenge for the Marlins, who fell to 4-16 on the season with an 8-3 loss to the Cubs on Friday. Miami totaled six hits in the setback, with three of them coming in the ninth inning.

It took the Marlins just three innings to fall into a 7-0 hole, and they never threatened the rest of the way.

“That’s a really good lineup, so when you’re behind, you’re giving them a really good chance,” Miami manager Skip Schumaker said of the Cubs.

Southpaw Jesus Luzardo (0-2, 7.65 ERA) will attempt to keep Chicago at bay in Game 1 of the Saturday doubleheader. Right-hander Roddery Munoz is expected to be called up from Triple-A Jacksonville to make his major league debut in the finale.

Luzardo escaped with a no-decision against the Atlanta Braves on Sunday despite surrendering five runs and seven hits in five innings. In four career starts against the Cubs, Luzardo is 2-0 with a 2.88 ERA.

Munoz has made three appearances (two starts) with Jacksonville this year, going 0-3 with a 10.97 ERA. He was acquired in a December trade with the Pittsburgh Pirates.

While the Marlins’ offense hasn’t adequately supported the pitching staff, Bryan De La Cruz has done his part and is currently riding a seven-game hitting streak. He is 10-for-29 (.345) with three home runs and 10 RBIs during that span, with one of those homers coming on Friday.

Chicago’s Garrett Cooper, who played for the Marlins from 2018-23, has hit safely in all six of his starts this season. He went 1-for-3 with an RBI on Friday.