c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = '2014-04-23 14:66:87 HEAP - [USAGE: 1948.3, FREE: 1400]; NON-HEAP - [USAGE: 611.9, FREE: 52.2]';
 ;;
 my ($f) = $s =~ m{ FREE: \s* (\d+) }xms or die 'no FREE';
 print qq{'$f'};
"
'1400'