Sabine Lisicki has been cleared to resume training after being diagnosed with mononucleosis over the summer. The former World No.12 and 2013 Wimbledon finalist told WTA Insider she had felt the symptoms of fatigue since early in the year and they got worse in April at the Claro Open Colsanitas, but continued to play through the clay and grass season before doctors were finally able to isolate the diagnosis to mononucleosis.

"I played matches, I was playing tournaments, but I didn't know what was going on," Lisicki told WTA Insider during the US Open in August. "I just felt like I was weak and I didn't know why because I did put in the practice, but everything was so hard. 

"I felt that something isn't right because my mind is there but my body wasn't following it."

"I was shocked when [the doctors] told me because I didn't expect that. You always hear about it and a lot of athletes have it, especially in the young ages, but I never thought I would get it one day too. 

"I guess I should be happy that they finally found out what's going on, because I haven't been feeling well for quite a while. So they kept digging and finally found out what's happening and why I'm feeling weak. 

The diagnosis was a frustrating setback for the big-serving German, who still holds the WTA record for the fastest recorded serve, 131mph, which she hit at 2014 Stanford. Lisicki underwent knee surgery in November 2017 and then sustained a foot injury in March 2018. Still highly-motivated to play herself back into the Top 100, Lisicki finished the 2018 season by making the final of the WTA 125K event in Taipei. She was finally injury and pain-free when she began to feel symptoms.

"At the beginning [when I started to feel symptoms], I thought maybe I'm not fit enough yet, because if you feel weak in a match that's the first thing you're thinking. I'm not the person who says oh, I'm sick, let's take the time off. I think ok, what can I do better. 

"We spoke to my team. It hasn't been easy because then you try and push yourself mentally. The mental part was right there. I wanted it. But the body wasn't there. 

"I still feel the fire and desire to play and compete. That's the way I approach it. As long as I feel that, that gives you the patience that you need." 

This week, Lisicki received word from her doctors that the mono has cleared her system and she can slowly begin her recovery and build-up to get back in competition, and she says she will return when she is 100% fit and ready to compete. 

"I still feel the fire and desire to play and compete. That's the way I approach it. As long as I feel that, that gives you the patience that you need. 

"But I definitely can't wait to be back on the court again. That's what I'm thinking about. There's nothing that I want more. Playing in front of my family, friends, and fans and fight for each point. I’m very thankful for their support in this difficult time."