Exactly. And given that the coworker was there before OP was, it's very likely that there's more going on than they see. I was in a similar situation (lots of

Exactly. And given that the coworker was there before OP was, it's very likely that there's more going on than they see. I was in a similar situation (lots of life stuff, manager of a team, accused of underperforming), and I had to deal with a lot of special requests because I knew basically everything at the company. When I left, my coworkers contacted me to say that they didn't realize how much I actually did and that they're surprised I was able to get as much done as I did. You don't know their situation, and you don't need to. Get your work done, help out where reasonable, but leave it at that. If the manager asks why things are late, be frank (I did my part and X and Y for coworker Z), but don't point fingers. It's not your job to fix the company unless you're primarily paid in equity (doesn't seem to be the case), and even then, there's probably a better way than trying to get someone fired (options you mentioned). We basically did what your suggested with another employee who was under performing, and once he got the right fit, he did much better. Sometimes it takes a third party to see your weaknesses and suggest a better fit.