Language problems with PL

I am issuing some problems with editing names in the tables:

I have changed in leaguemanager-pl_PL.po:

#: leaguemanager.php:710
#: show-league.php:78
msgid "Club"
msgstr "Zespół"

to:

#: leaguemanager.php:710
#: show-league.php:78
msgid "Club"
msgstr "Zawodnik"

but in the table, I still have: “Zespół” instead of “Zawodnik”.

Is there any other file I need to edit?

My website: http://www.fightrank.pl

https://wordpress.org/plugins/leaguemanager/