By Padraic Halpin
HAMAMATSU, Japan (Reuters) - Japan left captain Michael Leitch out of their starting team for Saturday's clash with Pool A favourites Ireland as a fit-again Amanaki Mafi took his place in the back row as one of five changes from their victory over Russia.
Japan struggled early on before running out 30-10 winners against Russia and coach Jamie Joseph on Thursday credited the impact experienced players like Luke Thompson had off the bench, with the lock being rewarded with a start on Saturday.
Joseph acknowledged that Leitch has had his injury problems this year but said the 30-year-old remained a key player whose experience would be even more crucial against a team who were ranked number one in the world until this week.
"Michael's obviously our captain but if we're going to be successful in achieving our goals, we're going to have to have impact and experience off the bench, all the best teams in the world have a great bench," Joseph told a news conference.
"If we're going to be in a position to win the match, it's going to come down to the last five or 10 minutes and we'll need clear leadership. As a coach, I get to have both things that we need, we have in form players who are playing very well and we have experience coming on."
Elsewhere in the pack, Jiwon Koo and Shota Horie come into the front row and Kazuki Himeno moves to flanker to make room for Mafi at number eight. South Africa-born Pieter Labuschagne captains the side from the other flank.
With winger Kenki Fukuoka still unavailable with a calf injury, Ryohei Yamanaka starts at fullback as Will Tupou shifts to the wing and Lomano Lemeki drops to the bench.
Joseph said he opted to put a bigger man on the wing to try and counter an Irish back three he described as probably the most experienced in world rugby and one that consistently creates a lot of pressure with an accurate kicking game.
Ireland will, however, be missing the experience of Johnny Sexton at flyhalf with Jack Carty set to make just his second start in one of four changes from the team that comfortably beat Scotland in their World Cup opener.
"I don't think we're the sort that can afford to be worried too much about whether Johnny Sexton is playing or not. To be number one (in the world), it's not one or two players that are quality, it's the squad," Joseph said.
"Whilst that (selection) was a surprise, it doesn't change anything that we need to," he added, saying his players would need to play the game of their lives to cause a shock in Shizuoka.
Japan: 15-Ryohei Yamanaka, 14-Kotaro Matsushima, 13-Timothy Lafaele, 12-Ryoto Nakamura, 11-Will Tupou, 10-Yu Tamura, 9-Yutaka Nagare, 8-Amanaki Lelei Mafi, 7-Pieter Labuschagne, 6-Kazuki Himeno, 5-James Moore, 4-Luke Thompson, 3-Jiwon Koo, 2-Shota Horie, 1-Keita Inagaki
Replacements: 16-Atsushi Sakate, 17-Isileli Nakajima, 18-Asaeli Ai Valu, 19-Wimpie van der Walt, 20-Michael Leitch, 21-Fumiaki Tanaka, 22-Rikiya Matsuda, 23-Lomano Lemeki.
(Reporting by Padraic Halpin; Editing by Amlan Chakraborty)