Freddie Ljungberg was back in training for the first time in nearly two weeks on Wednesday as the Sweden squad held its first workout since arriving in Japan.
"It still hurts a little bit," Ljungberg said of the aching back that forced him to miss Arsenal's final Premiership against Everton two weeks ago and Sweden's defeat by Paraguay in Stockholm last Friday.
After a lot of stretching and massaging, Ljungberg was able to train with the rest of the squad in a one-hour session at Rugby Field in the outskirts of Miyazaki, a small city of 300,000 people on Japan's southernmost island, Kyushu.
"It feels like I've got my strength back," Ljungberg said. "I was pretty tired toward the end of the season."
The 25-year-old midfielder, who scored seven goals in his last seven games as Arsenal completed its second league-cup Double in four years, hopes to play the entire match when Sweden face Japan in a friendly on Saturday in Tokyo.
"It shouldn't be a problem," he said. "I'm getting daily treatments. My back hurts if I'm playing games too frequently. I can take painkillers if needed, but I'd rather not use them."
Sweden missed Ljungberg badly in midfield as the team struggled against Paraguay. The Swedes also failed to impress in two earlier draws - 1-1 against Switzerland at home and 0-0 against Norway - with Ljungberg playing only one half in Oslo.
That was his first appearance in national team colours since Sweden qualified for a 10th World Cup late last year.
Two other Swedes, goalkeeper Magnus Kihlstedt and defender Tomas Antonelius, are getting back to fitness after sustaining leg muscle strains while playing for FC Copenhagen in the Danish League earlier this month.
Kihlstedt is Magnus Hedman's deputy and Antonelius is a reserve defender who is also not expected to start in the Group F opener against England at Saitama on 2 June.
Both worked out with a trainer behind one of the goals on Wednesday. Antonelius could be back with the squad on Thursday, but Kihlstedt will have to wait a few more days, coach Lars Lagerback said.
"The other players looked better than we had expected," Lagerback said. "It's not good to conduct long, hard workouts if players are jet-lagged.
"We have to adjust to the time difference. But we'll have longer workouts in the next few days before the Japan game.
The squad arrived late on Tuesday after a grueling trip from
Sweden that lasted nearly 20 hours with stops in Copenhagen and Tokyo.
Another game is scheduled for Monday against a local Miyazaki side before the England opener.