#!/usr/bin/perl -w
use strict;

my $team_file = shift || 'player'; # you can specify a team file on the command
                                   # line or take the default
my $scores = 'score';

# get players
open TEAM, "< $team_file" or die "Cannot open $team_file for reading: $!";

# the grep ensures that we actually have data
chomp( my @players = grep /\w+/, <TEAM> );
close TEAM;

# get scores
open SCORE, "< $scores" or die "Cannot open $scores for reading: $!";
my %all_scores = map {chomp;split/,/} grep { /[^,]+,[^,]+/ } <SCORE>;
close SCORE;

# get player scores for listed players
my %player_scores;
@player_scores{ @players } = @all_scores{ @players };

while  ( my ( $player, $score ) = each %player_scores ) {
    print "Player: $player\tScore: $score\n";
}