Rory McIlroy took to Twitter to throw his support behind Jordan Spieth, insisting the world number one is "not done" after struggling at the Valspar Championship.
Spieth's woes continued at Innisbrook on Thursday after the defending champion carded an opening-round 76 to fall nine shots adrift.
The 22-year-old two-time major winner's display came after he finished 17th at last week's WGC-Cadillac Championship, having missed the cut at the Northern Trust Open.
Many believe Spieth is in the midst of a "slump" but world number three McIlroy swiftly leapt to his rival's defence via social media.
"No, he's not TW [Tiger Woods], he's not slumping and he's not done," McIlroy wrote.
"He's a double major winning 22 year old. He'll be just fine!!"
Prior to February, Spieth romped to the Tournament of Champions title by eight strokes in January.
Spieth became just the second player in PGA Tour history to finish a 72-hole tournament 30-under par or lower.
He also placed fourth at the Hero World Challenge and tied for seventh at the WGC-HSBC Champions.