[1] Nicknamed Pitbull, Alas came through the youth ranks at Academia La Chelona and joined San Salvador F.C.
After sparking interest with his Gold Cup performance, Alas trained with MLS club CD Chivas USA in contemplation of a potential move there.
On December 27, 2007, it was announced that Dennis Alas had signed a one-year contract with USL-2 side Real Maryland F.C.
Alas made his debut for El Salvador in an October 2001 friendly match against Mexico and has, as of August 2011, earned a total of 63 caps, scoring 3 goals.
[7] On the night of June 7, 2007, he scored the game-winning goal against Trinidad and Tobago to give El Salvador their first win of their 2007 Gold Cup campaign.