The Spaniard joined Los Che on loan from Manchester City in the summer, but missed the start of the season with a foot injury.
Negredo returned on Saturday evening, however, as Valencia continued their impressive start to the season with a 3-1 win over Elche.
"This was an important win, I'm very happy to be back. It's been three very hard months. Now I need to find my rhythm and find my place in the team," Negredo told reporters.
"I was very excited to play. In the morning, I was like a kid and as the day went on I started to relax.
"These have been three very hard months and I appreciate everyone who has worked with me in my recovery, both in Manchester and here. The ovation from Mestalla made my hair stand on end."
It is understood that Valencia have the option to sign Negredo on a permanent deal at the end of this season.