The 21-year old USA international has reportedly emerged as a possible target for the likes of Liverpool and Manchester City but his domestic output has stalled as the Texan club has lost five of its past seven matches.
Dallas coach Schellas Hyndman feels that Shea, who has been representing the USA in their past few friendly fixtures, is perhaps suffering from fatigue amidst a streak of 10 games without a goal for his club.
"We'll have to wait and see how he is for the starting lineup," Hyndman said ahead of the weekend's home meeting with Vancouver Whitecaps.
"I still see a tired player. I think we've all seen his performance here be stagnant."