TOKYO -- South Korean pitcher Kim Kwang-hyun has pitched in some huge games for the country at earlier international competitions, but it won't get much bigger than the must-win affair against Japan at the World Baseball Classic Friday evening.

Kim was announced as South Korea's starter in the aftermath of the team's stunning, 8-7 loss to Australia in Pool B action Thursday afternoon at Tokyo Dome.

There are five teams in Pool B, with China and the Czech Republic being the others, and the top two after round-robin play will make the quarterfinals. Japan is widely seen as the favorite to win the group, and South Korea and Australia were expected to duel for second place.

A win Thursday would have made the rival showdown against Japan a relatively stress-free game for South Korea. South Korea could have afforded to lose to Japan and still reach the final eight, as long as it defeated China and the Czech Republic as expected.

However, the crushing loss means they must beat Japan just to have a fighting chance to advance to the quarterfinals.

Australia is expected to get the better of the Czech Republic and China. In that case, even if it falls to Japan, Australia will still finish at 3-1.

South Korea must win all remaining games to also end Pool B play at 3-1. Japan would be another team with a 3-1 record, in which case the teams will go to a complicated tiebreaking formula that rewards the team with the fewest runs allowed.

South Korea is already in a deep hole after giving up eight runs Thursday.

Against this backdrop, manager Lee Kang-chul turned to the pitcher with the most international experience on the team for its biggest game of the tournament.

"I felt we needed a veteran pitcher to set the tone in early innings," Lee said of the 34-year-old. "I know Japan knows him well, but I had to go with someone with his level of experience. I hope he gets the job done."

Kim has appeared in 16 international games, more than anyone on this year's staff, and has a 3.43 ERA with 57 strikeouts in 57 2/3 innings.

He had some strong outings against Japan early in his career, most notably at the 2008 Beijing Olympics when he held them to three runs in 13 1/3 innings across two starts.

But it has been mostly up and down since. Kim himself admitted in a media scrum Wednesday that he has had a mix of good and bad outings against Japan, while wondering aloud whether he still deserves a reputation as a Japan stopper.

Kim will have his hands full against the stacked Japanese lineup. Los Angeles Angels two-way phenom Shohei Ohtani leads the way, joined by Munetaka Murakami, who launched 56 home runs for the Tokyo Yakult Swallows last year, and Masataka Yoshida, who signed with the Boston Red Sox in the offseason after winning two Pacific League batting titles in Japan.

Kim will also be in a hostile environment at a packed Tokyo Dome, an intimidating setting even for a veteran like him.

Japan will counter with San Diego Padres ace Yu Darvish, a five-time All-Star and a two-time Cy Young Award finalist. The first pitch is scheduled for 7 p.m. Friday. (Yonhap)