Kyrgios picked up a niggling ankle injury in Dubai but has been made to defend his decision to withdraw from the United Cup.
The Australian No 1 doesn't play Davis Cup and has copped some flak in the media for his 11th-hour withdrawal from the team tournament.
"Anyone who plays professionally knows for sure," Kyrgios told The Sydney Morning Herald.
"Anyone outside of that wouldn't have a great understanding. Going deep or not, winning a match at a Grand Slam level is not an easy task. People underestimate the pressure and the nerves with being a part of one of the biggest tournaments of the year.
"Throw in an injury and knowing you didn't give yourself the best chance only adds to the mountain of pressure you face. So, feeling good physically is important."
Kyrgios insists that he kept the relevant authorities abreast of his situation.
"I was in contact with Craig (Tiley from Tennis Australia) and Stephen (Farrow, United Cup tournament director) regularly about the situation," Kyrgios explained.
"We all worked together to try and get the best outcome. Not everyone is going to understand or see it from my side and that is okay. What my team and I can control is how we go about our business and make sure who needs to know, knows - and we leave it at that.
"It is obviously very difficult. It's not ideal to have an injury at any time in the season, but that is the risk I run every time I step on court. I was working every day very closely with my team about my progression and speaking with William, my physio, after every session. I tried to be ready for it, but at some point, you need to listen to the advice you're receiving and do what is best."
Kyrgios has been backed up in this regard by United Cup tournament director Stephen Farrow.
"He left it to the last possible moment to confirm whether he was able to compete or not," Farrow said.
"These things happen in tennis, especially when you're two weeks out from a Grand Slam. This is a big event in its own right now.
"There's $15m [US dollars] prize money and 500 ranking points. But as a player, you have to keep one eye on the Grand Slams. The fact he was here practising, he had every intention to play. Sadly, it's not to be."