The Charlotte Knights’ top pitcher is heading to Japan. Here’s the likely lure.

Why would Donny Roach, the International League’s Pitcher of the Month in June, have left the Charlotte Knights last week to play baseball in Japan?

Roach had compiled a 9-2 record this season, with a 2.65 earned run average. He was leading or near the top of the league in several pitching categories. A few Chicago-area sports outlets were starting to talk about Roach being called up by the Knights’ parent team, the Chicago White Sox.

But Roach, who had been picked to pitch with the International League team in Wednesday’s Class AAA All-Star game, instead signed Thursday with the Orix Buffaloes, of the Nippon Baseball League’s Pacific Division.

There was no word from Roach or the White Sox organization on the reason, but money usually is the lure for U.S. players signing in Japan.

Roach, 28, had made 16 appearances in 2014 with the San Diego Padres, then pitched sparingly in 2015 with the Chicago Cubs and in 2016 with Seattle.

He pitched last year with the KT Wiz in the South Korean league, then was signed by the White Sox to a minor-league contract in January. According to the website payscale.com, the median salary for a AAA player is $78,614.

Overall, the Nippon Baseball League pays a lot less than Major League Baseball, with the top players getting about $4.5 million a season. But the average salary last season for a member of the Orix Buffaloes was $800,000.

Otherwise, here’s how the Knights’ week went:

Monday: Catcher Seby Zavala’s two-run single in the first inning was all the scoring that Charlotte could muster in a 3-2 road loss to Norfolk. Knights’ starter Spencer Adams was sharp, allowing only one run in six innings. Reliever Gregory Infante took the loss.

Tuesday: Zavala had another big game, going 3-for-3, but the Knights fell 4-0 to Norfolk. Starting pitcher Jordan Stephens allowed one run in six strong innings for Charlotte, but the bullpen faltered.

Wednesday: It was Zavala again. This time, he keyed a three-run sixth inning with an RBI double and later scored on a single by Dustin Garneau. The Knights treated an Independence Day sellout crowd of 10,831 to a 4-2 victory over Durham.

Thursday: Casey Gillaspie slammed two doubles, but the Knights fell 6-3 to Durham. Starter Michael Kopech allowed four runs in three innings pitched.

Friday: Jacob May got his team-best 14th stolen base of the season, but little else went right for the Knights in a 12-0 loss at Gwinnett.

Saturday: Spencer Adams pitched seven shutout innings as the Knights beat Gwinnett 5-0. Adams, who is from Cleveland, Ga., about an hour away from the Stripers’ home in Lawrenceville, allowed four hits in his strong outing.

Sunday: Eddy Alvarez opened a three-run, ninth-inning rally with a home run for Charlotte, but the Knights fell 5-4 to Gwinnett. The Knights entered the ninth trailing 4-1 but tied the game – only to have the Stripers win in the bottom of the ninth on a bases-loaded single.

Week ahead: The Knights, who finished the first half of the season 40-49, are off through Wednesday for the All-Star break. They open the second half with a four-game series in Durham, with evening contests Thursday through Sunday.