I don't remember seeing Markovic playing many first team games for us the last few years, he usually does pre-season then get's loaned out, so its hard to judge him when he's not playing alongside the likes Mane, Salah, Firmino etc.
Same problem we have judging Ings & Solanke as they usually get a chance when the top players are rested.
I expect he'll go on loan for the last year of his contract, I'd rather keep him and give him some time from the bench/Cup games, especially with Ox out and Lallana fitness an unknown.
The very few times I saw him play reasonably well was on the left wing, but Rogers pit him on the right. Anyway, he hasn't done very well elsewhere, so he must be having a problem, maybe confidence