Nationals general manager Mike Rizzo went to Houston on Tuesday to watch left-hander Aroldis Chapman work out, according to a baseball source.

According to Gene Duffey, an MLB.com contributor, Chapman had a bullpen session in the morning and impressed scouts with his velocity. Rizzo was not available for comment.

Chapman, 21, became a free agent after he defected from the Cuban National Team on July 3.

Whether the Nationals can sign Chapman remains to be seen. Rizzo said early this month that the Nationals most likely would not break the bank when it came to signing big-name free agents.