"Unfortunately, my hip has been getting worse for every match," Ljungberg said. "I'm limping a little bit, but I hope that the medical treatment will be effective.

"It hurts, but the World Cup is only every four years and I've played with pain before, both in England and for Sweden."

Ljungberg did not show up during the first 15 minutes -- the allocated time for media -- of Tuesday's training session at Miyagi Stadium.

The day before the England game, he took part in some drills. He trained as normal with the team the day before the Nigeria match.

"He's getting the same treatment as he received before the other games," said Swedish co-coach Lars Lagerback, admitting he's a question mark against Argentina.

Asked if Ljungberg's no-show in training means anything for the game, Lagerback said that "it was up to him if he wanted to participate in today's (light) training."

"If he can't play, we have a reserve plan. We'll make the decision later," Lagerback said.

Ljungberg set up the first of two goals by striker Henrik Larsson with a brilliant pass in the second half Friday against Nigeria, which lost 2-1 to Sweden and was eliminated. But "Freddie" also made several mistakes after the break.

"I felt fine after the Nigeria game, but my hip starting hurting again in the middle of the night," Ljungberg said. "It would have been nice to go all out in training."

Instead, Ljungberg had to skip the last training session Monday in Kobe before flying to Sendai, where the unbeaten Swedes need at least a draw with Argentina to make the tournament's knockout stage. They drew England 1-1 in the Group F opener.

"It's very difficult to go out and just play for a draw," Ljungberg said. "I think we're going to play our game and of course try to score, but at the same time not open us to wide. If Argentina scores in the beginning, it's going to be very, very difficult for us."

Ljungberg believes the key for Sweden is trying to neutralize Argentina's strong midfielders.

"What I've seen is that Argentina plays with three players in the back and five in midfield," he said. "So it's important that we keep it tight in midfield so they don't play through our lines or they play outside our lines.

"And of course we're going to try to exploit when they have three players in defense and try to do something about that. But it's very important for us to make a compact midfield because Argentina has a lot of players in midfield and they're very, very good with the ball. So it's difficult to take the ball from them."

Ljungberg, 25, injured his left hip nearly two weeks ago during at the team's training camp in Miyazaki City, southern Japan. Earlier in May, he was sidelined for more than two weeks because of a bad back.

The injuries could be a result of the grueling English season.

"I told myself in the spring that I would concentrate on Arsenal," he said. "I had been waiting so long time to win something with Arsenal and I didn't even think about the World Cup."

It paid off. He had a dream spring with the London side, leading Gunners' to the Premier League and FA Cup double and earning Player of the Year honors in England.

Ljungberg had seven goals in his last eight games for Arsenal, but he has been more of a passer than a big goalscorer for Sweden with only two goals in 34 games.