It's pretty easy to train them mate, find a player you like that you think could do the job and train them and play them there. It's not too different to a CB
There's a lack of sweepers in the game because it's a forgotten position. Long are the days where teams would regularly line up with a sweeper and that's reflected in the game.
Although many sweeper regens are made and it's easy to retrain CB's to sweeper.