foreach $fileToGet (@matches) {
  my $remoteFileSize = $ftp->size($fileToGet);
  $localFileName = "$fileToGet".".xxx";
  $ftpReturnVar =  $ftp->get($fileToGet, $localFileName);
  $localFileSize = (stat "$workingDir/$localFileName")[7];
    if ($remoteFileSize == $localFileSize) {
        push (@filesToRetrv, $ftpReturnVar);
    } else { ... }
}