"It's a #blessing!!! Should be 110% very soon and back to work. Thanks for the prayers and keeping me lifted!!! MUCH LOVE," Harris tweeted Wednesday, adding that, "Everything is fine."
Harris posted a photo showing the bandages after surgery was performed to remove the cyst. Coach Mike McCarthy shared no details about the procedure, but he did confirm that Harris will be unavailable for the remainder of the offseason program.
The Packers are confident Harris will be back by training camp.
Harris' agent, Dave Lee, told the Green Bay Press Gazette that the cyst wasn't cancerous, although it could have caused serious problems for Harris later in life if left untreated.
"The cyst was pressing against his lung, and now he has full capacity with his lungs so he should have even more endurance and speed, so it was a blessing in disguise," Lee said.
The cyst, which doctors believe Harris has had his entire life, was pressing on his lung, reducing its capacity, Lee said, according to The Associated Press. After doctors discovered it, Harris told them he'd occasionally felt pressure in his chest, but assumed it was indigestion.
After an impressive late-season run, Harris entered the offseason penciled in atop the Packers' backfield by committee. Now that second-round draft pick Eddie Lacy and fourth-round pick Johnathan Franklin have entered the mix along with healthier versions of Alex Green and James Starks, there will be no guarantees for Harris this summer.
The odds are stacking up against Harris now, but that's nothing new for an undrafted, undersized back who was working as a car salesman when the Packers called last season. Even with the lost practice time, our money is on Harris beating out Green or Starks for a roster spot.
Follow Chris Wesseling on Twitter @ChrisWesseling.