The Spanish winger had spent two months on the sidelines with a leg injury before making his comeback as a substitute in the goalless draw with West Ham United.
He admits it was a frustrating period after starting the season well, including a goal against West Bromwich Albion, but he is glad to have put himself in contention for this weekend's derby in Cardiff.
"This injury should have only lasted two or three weeks but when I started training I felt a problem in the same leg," Hernandez told the South Wales Evening Post.
"I had to re-start the treatment so it ended up being a long time.
"But it's fortunate for me that on Sunday I could play 30 or 35 minutes.
"I felt good on the pitch and I will train hard this week ready for the next game.
"Now I need more minutes to rebuild the confidence.
"The last game I played before the injury, against West Brom, I played good and I want to play the same in the next few games."
Hernandez is keen to play his part in a crucial game against Cardiff, but it remains to be seen whether Michael Laudrup will restore him to the starting XI.
"I think I should be able to train normally all week with the team," said the 28-year-old.
"Hopefully I'll be ready to start but it's not my decision.
"This game is very important for the club and most important for the fans.
"It's a difficult game because both teams want to win the match for the fans and the occasion should be unbelievable."
Watch Cardiff v Swansea on Super Sunday on Sky Sports 1HD, kicking off at 4pm