With the non-waiver trade deadline less than six weeks away, the cavalcade of scouting stars is underway. Tuesday night in Houston, sources say representatives for the Yankees, Giants and Blue Jays were in attendance as left-hander Wandy Rodriguez allowed two earned runs over seven innings in a 2-0 loss to the Kansas City Royals. The Astros will listen to offers for Rodriguez, sources say. Interested clubs are aware Rodriguez could have two years and $26 million left on his contract beyond this year, if he reaches the performance bonuses necessary to trigger the club option for 2014. Rodriguez, 6-5 with a 3.29 ERA this season, has made 30 or more starts in each of the past three years.