I Beleive that fglock is right, that your problem is that the variables in your regex($playertofind, $newplayer, $fileext), still have a newline on the end, so they dont match.

A quick way of doing this from the command line:

perl -pi.orig -e 's/Wonko/Bilbo Baggins/g' *.txt *.log
[download]

Found in "Perl Cookbook, CH 7" and in "Programming Perl"

Best Regards,
Wonko