Kensuke Kondo (right hamstring tightness) was taken off the active roster today. The Nippon Ham Fighters initially thought he might be okay after a few days, but decided he needed a little more time.
[UPDATE 6/14 @ 2:26pm]
Kondo started running exercises and played some catch today.
Source: Nikkan Sports 6/14/2017
[UPDATE 6/18 @ 9:40pm]
Kondo has not been able to resume batting practice because he still has tightness in his right hamstring. He might have the hamstring re-examined on June 20 if his condition does not improve.
Source: Sponichi 6/18/2017
[UPDATE 6/22 @ 6:16pm]
The Fighters announced today that Kondo was examined at a hospital in Sapporo and diagnosed with a herniated lumbar disc. When he was taken off the active roster on June 11, he also complained of lower back tightness.
[UPDATE 6/24 @ 2:22pm]
Kondo is considering surgery as an option, though he wants to avoid it if possible. If he goes under the knife, he could end up missing the rest of the season.