A few football player's, from high school to the Pro's will suffer pec tears, mostly line men or linebacker. Quite painful, and very limiting. Been around a few guy's who have gotten this. Know that some players have been out close to a year before they can get back to the shape there were in before the tear. Of course , you may be one of the lucky ones, with only a minor problem.
Assuming you went to a doctor to check it out, and not just a guess on your part. If the area is blue/black then you certainly have the start of a minor injury, or more serious, complete tear. The quicker the surgery the better.. There should be an area where you see a ugly bulge alone the chest area. That would suggest a complete tear, with the muscle being rolled up a bit.
Pretty hard to train around, because you should be finding out that the pec has a lot to do with about every exercise, including squats.
Guy's on deca, and like products, may tend to get muscle insert injuries. Like pec, bicep, tricep and quads, which all seem to be the most common.
Going to be up to you if you want to try and work around the pec injury. Only you will know what you can get away with...or not.
Good luck.