The Japanese international is keen to move up the pecking order at St. Mary’s, but he admits that he needs to improve.
“[I need to make] fewer easy mistakes and more concentration for 90 minutes and he (Koeman) said I need to improve concentration,” Yoshida said.
“I have two or three times made a very easy mistake, careless mistakes during the game, so I need to decrease those kind of mistakes.
“Then I will be a much better player.”
Yoshida’s task of breaking into Southampton’s team looks to be a tough one, as Virgil Van Dijk and Jose Fonte both have formed a strong partnership.
Fonte wears the captain’s armband for Koeman’s side, while Van Dijk has looked strong since moving to the club from Celtic last summer.
Yoshida did help Southampton pick up a victory against West Ham United at the weekend though, as he scored the only goal in the contest to provide Koeman's side with the three points.
Southampton have not conceded in any of their last five matches, and Yoshida will be hoping to keep his place in the south coast's side's defence for their match against Swansea City at the weekend.