Elena Delle Donne

Chicago Sky players Sylvia Fowles (l) and Elena Delle Donne (center) sit out a game against the New York Liberty. (E. Jason Wambsgans / Chicago Tribune / June 18, 2014)

Trying to relax in the players' lounge at Allstate Arena after another late June loss, Sky forward Elena Delle Donne's frustration was starting to show.

She has been battling debilitating headaches and exhaustion. The Sky have dropped eight of their last 11 games, and the reigning Rookie of the Year is trapped on the sidelines.

"It's something I'm struggling with," Delle Donne said. "I'm trying to find a way to continue to motivate the girls even if I'm not out there with them."

Delle Donne won't get angry about her condition, which she identifies as chronic flare-ups of Lyme disease. That would distract from her bigger goal, the one that starts with her recovery and ends with a WNBA championship. So Delle Donne focuses on what she can control.

"I'll mold into the leader I need to be to get this team winning games," Delle Donne said.

A week later, as the Sky were heading to New York after another loss, Delle Donne was boarding a plane home to Delaware. The treatments in Chicago were no longer enough, and the season was beginning to crumble.

Delle Donne is suffering, that much is certain. Keeping her healthy has become first on a long list of needs for the Sky, who have played just one game this season at full strength. Delle Donne's diagnosis, however, is a bit more controversial.

While Lyme disease is real, a bacterial infection chiefly transmitted by ticks, most medical professionals say there is no strong scientific evidence that it exists in a chronic form that evades the accepted treatments.

Some doctors who diagnose and treat chronic Lyme disease have been disciplined by their state medical boards, as revealed in a 2010 Tribune investigative report.

Delle Donne was treated for Lyme disease in 2008. So far, doctors have struggled to come up with an answer for why her symptoms keep returning.

Delle Donne declined to give specific details about her doctors, or the treatment they provide. She did say that the care she receives is based on her symptoms and the decision of how, and when, to handle them occurs on a week-to-week basis.

Some days you'd never know she was ill. Others she can hardly get out of bed. And for a team in need of consistency, adjusting to anything but that has become the norm.

Franchise player

The Sky list Delle Donne as a guard/forward because it's becoming increasingly tougher classify where she plays. At 6-foot-5, she has the size to post up down low, backed with a jump shot that's seldom out of range. But that's not why Sky general manager, and coach, Pokey Chatman values her.

"We can play multiple defenses," Chatman boasts. "She's a player who changes the entire game plan."

Those skills are why Delle Donne was included in the WNBA's "3 To See" campaign alongside league stars Brittney Griner and Skylar Diggins before the 2013 draft. Those skills helped carry the Sky to the franchise's first playoff appearance in the season that followed. And that's why she became the first rookie to win the All-Star vote in WNBA history.

That's what gave the Sky so much hope when she returned for the start of the 2014 season playing the best basketball of her career. Even with starters Epiphanny Prince and Sylvia Fowles recovering from injuries at the start of the season, the Sky raced out to a franchise-best 5-1 start, with Delle Donne averaging more than 23 points per game.

A back-to-back against the Los Angeles Sparks at home on June 6, followed by a game in Atlanta the next night changed that.

Against the Sparks, Delle Donne matched up against two-time WNBA Most Valuable Player Candace Parker and notched a career-high 33 points and 14 rebounds.

But 24 hours later in Atlanta something wasn't right. She was depleted. She said she was feeling like she did two years ago when similar symptoms flared up during her senior season at the University of Delaware. She felt like she did two years before that, during her sophomore season, when doctors struggled to figure out what was wrong. She felt like she did in 2008, when she was first diagnosed with Lyme disease.