The Cubs are no closer to finding common ground on a potential contract extension with pitcher Jeff ­Samardzija than they were a year ago. In some ways, they’re further apart. He is considered the club’s top commodity for the July trade market, but could he be dealt before the season starts in five weeks? Two industry sources said Monday they believe a trade is a strong possibility, although a third source said no such talks are happening. Cubs manager Rick Renteria did little to quell the notion when, for the second time in a week, he declined to acknowledge the ­obvious choice when asked about the possibility of Samardzija getting a second consecutive start on Opening Day. “So many things can happen over the course of the spring that I’m not going to lock myself into trying to divulge something that I can’t really determine will be in the end,” Renteria said. If that was a reference to injury potential, it was lost in Samardzija’s elephant-in-the-room status with the club — especially with several teams, including Texas and Toronto, still in the hunt for starting pitching and so far reluctant to spend on lingering free agent Ervin Santana.