Infeld originally intended to pursue graduate school at Georgetown University for the 2012–2013 academic year; however, she was not feeling fully invested in her graduate program, and with her college coach Chris Miltenberg and many training partners moving elsewhere, she decided to turn pro joining Kimbia Athletics (officially announced October 2012) and move to Portland, Oregon to work under coach Jerry Schumacher at the Bowerman Track Club. She began training alongside American Olympians Shalane Flanagan and Kara Goucher where she struggled to adapt to the strict training schedule at first and missed parts of the 2013 season. However, she placed 4th at the 2013 USA Cross Country Championships to qualify for the 2013 IAAF World Cross Country Championships and placed 21st – a key member of the United States fourth place team. In November 2013, she was diagnosed with a stress fracture in her sacrum on the left side, and again had to take time off from running. After taking months off, she was beginning to progress with her career again, but on December 2014, she suffered another stress fracture of the sacrum; this time on the right side. She was unable to run on foot again until about 6 weeks before her first race back from injury on May 3, 2015.