Yes. Major. I work as a manager at my workplace, and have several employees to attemd to. If one performs like crap, and everyone else are trying, but constantly see that one employee being able to keep hts or her job whilst slacking and under performing, that will quickly fester demotivation amongst others. It happens to the best. Rotten apples will affect the rest of the batch.
So not only are they a problem in terms of their current form, they are also aiding in festering a rotten and unambitious culture at United, due to Erik constantly picking them - despite their sloppy performances.
Should be benched as quickly as possible.