It’s debatable whether or not a team needs to play “perfect defensively” to beat Japan as Australia manager Jon Deeble lamented after his team’s 10-3 loss on Sunday night.

First, it helps to not commit four errors or allow five unearned runs the way the Australians did, but that same Aussie squad was far, far from perfection when it was five outs and one ill-fated pitch from beating Japan Saturday night, instead falling 3-2 after Ryoji Aikawa’s three-run homer in the eighth.

What you can take out of the teams’ two-game series is that at least someone, anyone, on the Japanese team may indeed need to play a perfect game if the Samurai are to bring home the World Baseball Classic title for the third consecutive time

Japan is the two-time defending champion, but will have to play the scrappy, gritty game of an underdog during the WBC.

Japan will need to keep its nerve and survive a few nail biters, as in Saturday’s 3-2 win, while punishing its opponents for their mistakes, as was the case Sunday. Pure skill should push Japan into the second round, where the Australians say they’ll be waiting, but Japan won’t be able to get away with disjointed performances after that point.

Someone, a few someones actually, will have to step up and light the fire, night after night, game after game, as the pressure to three-peat builds with each passing day.

Offensively, Japan can’t be counted on a consistent basis, and while Sunday’s 10-run outburst led to relieved smiles all around, it was aided by four errors and an Australian starter who had pitched one inning since September, and was hardly in peak condition.

More troubling are the struggles starters Masahiro Tanaka and Kenta Maeda continue to have on the mound. Both have put together solid innings but have yet to deliver a wholly solid outing, with their next chance to do so coming when the games actually count.

On the bright side, the majority of the pitchers behind them have delivered. Atsushi Nomi has been the standout of that group, which also includes Toshiya Sugiuchi, Kazuhisa Makita, Takeru Imamura and Masahiko Morifuku among others.

“Each of them had positive outings, so that was good,” Japan manager Koji Yamamoto said. “We still have some guys who haven’t pitched, but these all faced some tense situations and can work with more composure next time.”

The WBC’s 65-pitch limit in the first round (which will be upped to 80 in the second) means the second-tier of pitchers have to perform, but their roles take on greater importance should Japan fall behind early after another shaky start by Tanaka or Maeda.

Among the position players, Seiichi Uchikawa, one of the few holdovers from the 2009 squad, was the only one of Japan’s star players to deliver over the weekend. The rest of the dirty work was left to the backups.

Aikawa was the hero Saturday, with the aforementioned three-run homer — after hitting just two in 629 at-bats for the Tokyo Yakult Swallows the past two seasons — that bailed out a team having a dismal night at the plate.

Sunday, Kazuo Matsui, newly inserted into the starting lineup, sprinkled a three-run triple and sacrifice bunt into a productive 2-for-4 night, with Katsuya Kakunaka also going 2-for-4 in another win.

Operating at a high level is not limited to the players on the field. Yamamoto, who guided the Hiroshima Carp to the Central League pennant in 1991, presiding over the final vestiges of the team’s last golden era, is going to have to push the right buttons.

After Japan was held in check by the Carp in a practice game Feb. 17, a 7-0 loss, and by the Australians most of Saturday night, Yamamoto jump-started his stagnant lineup by moving players around and inserting Matsui and Kakunaka into the lineup, and was rewarded for his efforts with 10 runs, though even that felt like more of a band-aid than a cure.

“I told both of them that this wasn’t the last game they’d play,” Yamamoto said, referring to Matsui and Kakunaka. “This game gave me confidence that I can use various types of lineups.”

Perfection, or near-perfection, is a fine line to walk, and most of the time a defending champion operates from a position of power.

This Japan squad however, isn’t the 2006, or the 2009 team.

The name across the front of their uniforms demands respect, but it means nothing once the first pitch is thrown. Japan can’t afford many letdowns and will have to be at its best, if not nearly flawless, if it hopes to extend its reign as world champion.