Elasticsearch unassigned shards

If it gets rebalanced it will clean by itself the space occupied for the old shards?
Because it worries me the fact that for the elasticsearch-1 the disk.used is much bigger that the disk.indices.

   shards disk.indices disk.used disk.avail disk.total disk.percent host          ip            node
   119      119.1gb   587.1gb     67.3gb    654.5gb           89 10.224.10.85  10.224.10.85  elasticsearch-2