Haas started the season at the Heineken Open in Auckland, where he lost in the second round against Jack Sock in straight sets. At the Australian Open, he was forced to retire with a recurring shoulder problem against Guillermo Garcia-Lopez in the first round after trailing 5–7, 2–5 on serve. After the setback, he participated in the first round of the Davis Cup against Spain. He teamed up alongside Philipp Kohlschreiber in doubles, taking a four-set victory to hand Germany a place in the quarterfinals for the first time since 2011.