The fly-half, who played four times for the Scarlets, has played most of his rugby at inside centre for the Exiles. London Irish will be desperate for a victory after their disappointing home defeat to Edinburgh last weekend.
"It'll be nice to go back to Wales and put down a marker," said Shingler.
Shingler, whose' older brother Aaron will line up for the Scarlets for their daunting ttip to face Northampton Saints at the same time on Friday as he will be in the Welsh capital.
"I'll go home for the weekend and it'll be nice to go back and see the family and hopefully it'll be an enjoyable weekend instead of a depressing one," said. Shingler junior.
"It'll be nice to show that I'm still here and in the mix and hopefully I can put in a good performance and get people talking about how well I performed and show them that I am one for the future.
"It was a big decision to leave Wales and move away from home. Mike Catt (backs coach) is here and I felt I need to move here to reach my goals.
"It is a dream to play international rugby and what you aspire to do. I've not had any contact and I know it is tough to get into the Wales reckoning when you move away but I am playing every Saturday and that is what I enjoy.
"It's worked well (the move) and my form is pretty good and I've had a lot of game time. I've managed to play well enough to keep my place.
"Mike Catt has pushed me and tested new boundaries and it's worked out."