Gaining Upper Body Muscle with Knee Injury

I want to add some muscle on my upper body. Problem is I am beginner and I had knee surgery. I can not lift weights standing or do deep squats (can not bend knee past 90 degrees) not to mess my knee. I will be able to do that in few months.

For now I need to have some program to gain muscle size. My overall goal is +10 kg. Currently I am 185cm high and 82 kg. I am beginer when it comes to body building – but I did a lot of sports before my injury.

Can you recommend me any workout plan?

You can look at @T3hPwnisher’s training log. Dude tore his acl and found ways to not only work around it, adding mass to his upper body while staying relatively in and getting enough posterior chain work in that he is able to get back into squats/deadlifts fast once cleared from rehab.

Try the upper body workouts from this below - the volume will balance out not doing legs

(its fine replace a standing move like hammer curls with seated or drop entirely)