Manager Torey Lovullo did not commit to Nelson making his next scheduled start, Theo Mackie of The Arizona Republic reports.
Nelson allowed 10 hits and five earned runs across four innings and took the loss in Thursday's game against the Phillies. He has had inconsistent results this season and has particularly struggled with walks of late, giving up 15 free passes across his last 31.2 innings while striking out only 20. It's unclear who the team would tab to take his place, though Drey Jameson has pitched in long relief -- he threw 2.1 scoreless innings Thursday -- and Brandon Pfaadt could get a second chance in the big-league rotation.