It was determined that Nishioka's fibular fracture will not require surgery or a cast, but that a timetable for his return will not be set until the soreness and swelling subsides.
"It's still a fracture, but it's not a huge injury that will force me to miss the season or anything," Nishioka said through translator Ryo Shinkawa. "I just want to get back as soon as possible."
Nishioka has crutches to help him get around.
Twins manager Ron Gardenhire said Nishioka was upset that the injury forced him to miss playing in the home opener at Target Field on Friday. Gardenhire said he expects Nishioka to miss four to six weeks.
"We were hoping our fans would be able to see him on Opening Day, and for Nishi too because he was very excited about coming home," Gardenhire said. "So it's very frustrating and disappointing for Nishi and our fans. But they'll get a chance [to see him] after he gets healthy and is back on the field."