Will Sweden's man of mystery pose problems for USA?

GOTHENBURG, Sweden -- It's hard to fathom how an eight-month injury layoff could be ideal preparation for a best-of-five-sets Davis Cup semifinal match against the world's fifth-ranked player. Yet that's how Swedish captain Mats Wilander is spinning Joachim Johansson's return to active duty Friday.

The big-serving, 6-foot-6 Johansson, a somewhat erratic player even when he's healthy, will open up the weekend competition Friday against Andy Roddick. Wilander contends the fact that Johansson has been shut down since the Australian Open last January actually could put the U.S. team at a disadvantage.

"They haven't seen him," Wilander said. "They don't know where he is. They don't even know if he's playing the same way he was playing before.

"There's no limit to how well he can play and no limit to how bad he can play. That's what he has to improve on. He gives you no rhythm. You will never feel good no matter who you are."

That rationale hinges on a couple of pretty big ifs -- if Johansson is really physically sound, and if he doesn't jeopardize his future by pushing himself too hard, too soon in a pressure-filled situation.

Johansson brushed away that speculation Thursday, saying he's felt good in practice, although he admitted there's no telling how his body will react to match play. Still, "I've been injured so long, I wouldn't risk anything with my shoulder if I wasn't ready," said the 25-year-old, who reached a career-high No. 9 in early 2005 but has never fully recovered from shoulder and elbow surgeries later the same year.

Nicknamed "Pim-Pim" after a younger brother struggled to pronounce his first name, Johansson might more properly be called "Bam-Bam" when his serve is on. He's the son of Leif Johansson, a former player whose brief career was similarly marred by injuries.

Although Johansson and Roddick have played just twice at the ATP level, they're well acquainted. They were born less than two months apart, came up through the junior ranks together and reached the junior French Open doubles final as a team in 2000.

"He's going to come out and play high-risk tomorrow," said Roddick, who has had the benefit of hitting with two exceptionally tall practice partners, 6-foot-6 Sam Querrey and 6-9 John Isner, in the week leading up to the tie. "I don't think he's going to want to get into a lot of long rallies.

"I feel like he's going to go big on first and second serves. He's got nothing to lose out there. I've got to just stay the course and play my match solid the whole way out and take my chances when I get them."

The truth is that even if Johansson winds up being a sacrificial lamb, he also represents the tactical linchpin that handed Wilander -- seemingly boxed in by a gimpy player pool -- the best possible matchups under the circumstances against a powerful and favored U.S. team.

Wilander had little choice but to name Johansson to the roster after the country's current top player, Robin Soderling, had to beg off with a sore wrist. Sweden lacks depth at the moment, to put it tactfully. That left Wilander with a quandary -- ask 35-year-old veteran Jonas Bjorkman to play three matches in two days, or roll the dice with Johansson.

Here's why the latter made sense, and why U.S. captain Patrick McEnroe wasn't surprised by the move:

• Davis Cup fixture Bjorkman gets a day of rest before playing Saturday's crucial doubles match with unaccustomed partner Simon Aspelin against the world's No. 1 team of Bob and Mike Bryan;

Thomas Johansson (no relation to Joachim), recently thumped by Roddick at the U.S. Open and 0-5 against him lifetime, doesn't have to play him on the first day;

• And Wilander still has Bjorkman in reserve for Sunday's reverse singles if necessary.

Thursday's draw that determined the order of play fell Wilander's way as well, he said. After being sidelined for eight months, Joachim Johansson knows exactly what time he'll take the court instead of having to wait around for a second match. If Bjorkman is pressed into service Sunday, it would be in the fifth and decisive match, where his experience could be precious.

There's also the small matter of what happened the last time Roddick and Joachim Johansson met, at the 2004 U.S. Open. Johansson toppled the defending champion in the quarterfinals in five sets after Roddick took a two-set lead.

The two men combined to blast 64 aces. Roddick had 34 of them, but the difference came on break points, where he converted on only three of 15 opportunities while Johansson made good on three of his five. Johansson's win -- Lleyton Hewitt subsequently stopped him in the semis -- marked by far his best performance in a Grand Slam event.

"That was a long time ago," Roddick said Thursday. "A lot has happened since those matches." Indeed, while Johansson spent long stretches completely idle, Roddick fell out of and then regained top-10 form while twice changing coaches and diversifying his game.

Johansson does have one encouraging precedent for rising from the ashes. He played only one ATP-level match during the first half of 2006, warmed up in the late summer and fall with a few lower-level events, then shocked No. 2 Rafael Nadal in the second round of the Stockholm Open in October. Johansson proceeded to upset then-fifth-ranked Nikolay Davydenko at the Masters Series event in Madrid.

After reaching the semifinals of this season's curtain-raiser in Adelaide, Australia, Johansson retired after playing just two games of his first-round match in the Australian Open and faded back into medical limbo.

"You know what he's going to do -- you just don't know how well he's going to do it," Wilander said of his not-so-secret weapon. "Joachim is very confident. He knows he's beaten Andy in the biggest stadium in the world, on his home court, when he was ranked No. 2 at the time and defending champion."

On the fast indoor carpet at the Scandinavium arena, Wilander said, "You can play for an hour and a half and you haven't actually made a shot. You've served. You have no rhythm. Everybody hates playing against Joachim."

Energy equals McEnroe squared: A McEnroe is on the way to setting what could be an unofficial Davis Cup record -- John McEnroe Sr., that is, father of John and Patrick. The U.S. versus Sweden tie marks the 55th Davis Cup weekend attended by the patriarch, who has been present at every competition in which either of his sons played or was team captain. Mac Senior has traveled to 17 different countries and 27 U.S. cities in support of his sons, and even went to Palm Springs, Calif., last year to watch the U.S. beat Chile when Patrick McEnroe took the weekend off while awaiting the imminent birth of his daughter. The U.S. team is 42-12 in competition with him in the stands.

Bonnie D. Ford is a frequent contributor to ESPN.com.