At UFC 140, in the co-main event of the night, Ricardo Lamas took on Darren Elkins. Coming off the back of a bad run, Lamas was under pressure to get a victory in the fight. In this he was successful, knocking out Elkins late in the third round. Now, it appears there were other forces at play as well.

Ricardo Lamas knocked out Elkins after dominating him for most of their fight in UFC Argentina. Since then, Lamas has taken to Twitter to make his condition heading into that fight clear.
— Ricardo Lamas (@RicardoLamasMMA) November 21, 2018
It appears that Lamas was not completely fit during the fight as during his first day in Argentina he had noticed that his leg was tight and sore. Thinking it was nothing other than a muscle pull, he kept training. The day of the fight the condition had really worsened. Upon examination, a blood clot was found in his leg.
“It turns out I formed a blood clot in my calf muscle during the flight to Argentina from being seated in a tight area for so long. Things could’ve ended badly if the clot became dislodged during the fight.”
Thankfully, things worked out for the better, and no complications arose, allowing Lamas to even finish Elkins, while fighting with a complication.