The new Fox series focuses on a con man, played by James Wolk, leading a double life in Texas.
Entertainment Weekly reports that MacDowell, who is best known for her role in Four Weddings And A Funeral, is on the verge of signing a deal to appear on the show.
She would allegedly play the love interest of Clint (Jon Voight).
Meanwhile, Make It Or Break It star Rosa Blasi has reportedly landed a recurring role in the series. She will star as Blake, the wife of Trammell (Mark Deklin).
Lone Star premieres on September 20 on Fox.