The England defender returned to the side for Saturday's 1-0 win over Stoke after several weeks on the sidelines nursing a deep gash suffered against Reading.
He needed a pain-killing injection to face the Potters but with his side desperate to make up ground on fourth-placed Chelsea - now four points ahead - the centre-back insisted needs must.
"It's not quite healed up yet but it will get there and I can play without any problems," Jagielka told the Liverpool Echo.
"I've got to have an injection to take a bit of the pain away because there's still a bit of scar tissue but it's part and parcel of being a footballer.
"I've been desperate to get back training and playing with the lads. It's a boring time being on your own, especially being injured.
"I've been there before and so it's been nice to get back amongst it this week, even more so to play."
Jagielka returned as part of a rejigged defensive formation, as boss David Moyes deployed three central defenders and used Leighton Baines and Seamus Coleman as wing-backs.
"The manager has had a big decision to make with the players who are fit and are available," he added. "We've talked about doing it for many months with me, Johnny (Heitinga) and Sylvain (Distin) being fit for the majority of the season.
"The manager decided to do it and I think it worked quite well, mainly because of the two wing-backs who played left and right. They have such great energy, as shown in the last few minutes when Seamus ran the ball out of play.
"As much as we enjoyed it as a back three, you have got to take your hat off to the two boys on the wing for doing all the donkey work.
"You find yourself going into different areas, especially with Sylvain and Johnny playing on the outside. I thought they both did really well and as a team we are delighted."