The Dynamo acquired central midfielder Collen Warner in a trade Wednesday with Toronto FC.
Houston sends a 2017 conditional second-round pick to Toronto in the exchange.
Warner, 27, played in 49 matches for Toronto over the past two seasons with 39 starts. Before being traded to Toronto in May of 2014 Warner started nine matches for Montreal. In 2015 he had two goals and two assists in 29 matches.
The Denver native was selected by Real Salt Lake in the first round of the 2010 MLS SuperDraft. He played two seasons with RSL before being selected by Montreal in the 2011 MLS Expansion Draft.