Healing takes a little time, so just don't go crazy with these things, but the key to lat health and size is that they are flexible not tight. So first, a stretch: Hold onto a door frame or squat rack (the upright). Your grip should be at waist level. Then squat down and push your hips back as far as possible from the bar. So you're basically hanging back. From there it's important that you try to move around a little bit. Lean left and right, twist slightly, etc. The lat is fan shaped so different directions will give a more thorough stretch. You can also grab the post with both hands to stretch both simultaneously. You can REALLY stretch the lats.
Next, it's time to take that flexibility and do DB rows with perfect technique. This does not mean that you should be absolutely rigid and isolate the motion--that's for the skinny personal trainer at the gym. I prefer to kneel one knee on a bench, spread the other foot wide enough so my hips are level and my knee is bent. From there I always reach all the way to the floor. You should feel the lat stretch and you should feel the shoulder blade stretch away from your spine. Do not reach across the body or twist with the DB, reach straight down from the shoulder or even wider. The rowing motion should then start with the shoulder blade retracting back toward the spine, the lat should then pull the elbow back and IN. It shouldn't row away from the body, but right alongside and then squeeze in or back. I like to use a weight where I can do about 10-12 smooth and controlled full ROM and then start pushing off slightly with my off leg to cheat for a few extra reps. The total usually being 15-20
So stretch and then when you work the lat let it stretch there too. If it doesn't stretch when you row, it won't stretch well when you deadlift, and could have led to the strain