Dominic Thiem said he will take he will use his upcoming break as a chance to reset after the world No 4 admitted he is going through a "tough period". The Dubai Duty Free Tennis Championships top seed crashed out in the second round – his first match after receiving a bye – to South African qualifier Lloyd Harris on Tuesday. As the 6-3, 6-4 scoreline suggests, it was a comfortable victory for world No 81 Harris as Thiem struggled to impose his authority on the match. The defeat extended a struggling start to the season for the reigning US Open champion, who lost convincingly in the Australian Open fourth round and in the quarter-finals – his second match – at the Qatar Open. His current win-loss record for the year stands at 5-4. Thiem has opted not to travel to the United States for next week's Miami Open, preferring instead to prepare for the clay court swing, culminating in May's French Open, and the Austrian will use the extended break to regroup. "I just need to reset a bit to go fresh into the clay season," Thiem, 27, said. "Right now, I’m in a tough period so it wouldn’t be the right thing to go to Miami, so it’s better to regroup and hopefully have a good clay season. After these tough weeks that’s my main goal now." Thiem has been troubled by a persistent foot injury, but he insisted that his fitness was not the reason for his loss in Dubai. "There was no pain in the foot," said Thiem, who is twice a finalist at Roland Garros. "It’s a bit on and off and I’ll do an MRI just to see but it’s not the main issue. I’m just not playing well. It’s a tough period for me, so I need to start fresh and be ready for the first clay tournament, wherever I’m going to play."