use warnings;
use strict;

while (<DATA>){
    if (/^(\w+).*\s(\w+)/){
        my $line = "$1,$2";
        print "$line\n";
    }
}

__DATA__
SWA vs CHE GK
WBA @ BOU GK
EVE GK
EVE 4 87 dwqer *** GK

##</code><code>##

SWA,GK
WBA,GK
EVE,GK
EVE,GK