Legendary sportscaster Ernie Johnson has just announced he will NOT be covering the MLB playoffs for TBS ... after doctors diagnosed him with blood clots in both of his legs.
The 62-year-old says he was undergoing a routine physical when doctors found the clots -- which can be fatal if not treated immediately.
The danger with blood clots ... they can break off and enter the blood stream and, in some cases, can cause a pulmonary embolism, which is a blockage of an artery in the lungs.
Johnson says he understands the situation -- and he's treating it aggressively with blood thinners and compression socks.
Flying in planes can be dangerous when diagnosed with clots -- and since Johnson would be taking a bunch of flights in a relatively short time period, his medical team advised him it wasn't worth the risk.
"The best course of action is to just stay grounded at this point, not fly," EJ said ... "blood clots are nothing to be messed with."
While recovering and treating the clots, Johnson says he'll be preparing to cover the NBA when the season kicks off in just a few weeks.
Get well soon, EJ!