I work in a huge company in a relatively large team of people and every week we perform small weekly projects in teams of 2-3 random people. Now recently I am being planned multiple times with colleague who is junior (he is at the company for 1.5 years already), while I am being senior (I have 3 years of experience).
The problem is, that I really dislike working with him. I have no problem mentoring a junior, guiding and helping, and I understand this is partially my job during that small project, but this guy is completely unmotivated, lazy and works extremely slow. He is a good person, but it never seems like he is willing to learn something new or try to do him job somewhat fast. Instead he is checking his phone every 2 minutes, constantly yawning and takes forever to do basic stuff, even though he knows how to do it. It feels like he spends 15% of his day on a phone. I was giving him tips on how to do stuff more efficiently, and he agrees with me but in the end there is no improvement.
What complicates this for me is that at the end of a weekly project we have to provide a deliverable report, and I cannot just say it's not delivered because of him. We have to deliver it no matter what, and since I am senior it's my responsibility it's delivered on time and in a good condition. So essentially if he works slower, then I have to work more to make up for it.
I was wondering, would that reflect negatively on me if I would ask our planning team or management to preferably not plan me with him too often? Or is it unreasonable request from me? Keep in mind that our team is large, so there are always other people who can be planned instead of him.