Blind, 29, underwent heart surgery on Dec. 21 after experiencing dizziness in Ajax's 1-0 Champions League loss to Valencia on Dec. 10, but he returned to action in the 77th minute for Ajax on Wednesday.
"I am really happy to be back on the pitch," Blind told Fox Sports Netherlands. "I was so eager to get back. I had a little bit of tension beforehand because you don't know how it will go. But I knew before the match that I would come on, so I looked forward to it."
The procedure Blind underwent in December saw the former Manchester United defender fitted with a subcutaneous implantable defibrillator, according to the club.
Blind said: "It was heavy period because you don't know what is coming or which news you will get but luckily it didn't last long for everything to look good. I have been positive most of the time and was busy with my return.
"The doctor really needed to hold me back and step on the brakes because I wanted to get back asap. I wasn't scared at all, I wanted to get back on the pitch as fast as possible.
"I have missed [playing] a lot. I missed my teammates and I missed being on the pitch. I need to build up now, I am not fully fit to play 90 minutes."
Ajax, who missed out on the Champions League round of 16 after making it to the semifinals in 2019, next face RKC Waalwijk in the Eredivisie on Feb. 16.