Hainault, 22, has been with the Dynamo for the past two months as final details of his loan were completed. He played with FK SIAD Most in a regional league and the national second division, and had gone on loan to Sparta Prague since leaving the Montreal Impact in 2004 after playing just three games for the USL-1 club.
According to a Dynamo press release, terms of the deal had been agreed in early March, but a dispute between Hainault and the club prevented receipt of his international transfer certificate. MLS signed him as an out-of-contract player but SIAD Most claimed it still held his rights.
Upon release of that document by the Czech club, his MLS contract - a four-year deal that will pay him a base salary of $99,000 this season - officially takes effect. He holds Canadian citizenship and will occupy a senior international slot as a discovery player.
The native of Hudson, Que., has played 14 times for Canada and scored one goal. He also represented his country at the 2005 FIFA U-20 World Cup. With starting defender Eddie Robinson out until midseason with a knee injury, Coach Dominic Kinnear has been using second-year players Julius James and Geoff Cameron as central partners for Bobby Boswell while he awaited the Hainault deal to be finalized.
Hainault is expected to be on the 18-man game-day roster and might get a starting assignment when Houston plays Colorado Sunday at Robertson Stadium.
"We're very pleased to officially have Andrew joining the team," Dynamo Chief Operating Officer Chris Canetti said in the team release. "He's a promising young defender with international experience who will add depth to our back line and hopefully make an immediate impact."
Houston (0-2-2) has yet to win a game this season and its normally stingy defense allowed four goals in the first two games, though it did post its first shutout of 2009 last week in a 0-0 tie with New York.
English forward Ade Akinbiyi, 34, trained with the team for the first time Monday, then flew back to England to have his work visa stamped at the U.S. Embassy. Under U.S. immigration law a P-1 visa must be issued in the subject's native country or his place of last employment. Akinbiyi has been playing in the lower tiers of English soccer since starting out as a trainee with Norwich in 1993.
Though born in Hackney, a borough of London, he is of Nigerian heritage and represented that country once. If he completes his paperwork and recovers from a second cross-Atlantic trip in a few days, he, too, could be available to face the Rapids Sunday.
"The other forwards have been doing well, so hopefully adding me will put pressure on each one of us to do well," Akinbiyi said on the team's Web site. "I've got to try to fit in, blend in with the guys, and help the team."