In my experience I have found that it is very difficult to gain strength and muscle mass during a wrestling season. Heavy lifting is probably not a good idea when you are putting your body through intense wrestling practices every day. In season, the focus should be on maintinence. I would recommend a circuit training type of work out. I would make it fast moving, high reps, 2-3 days a week. These lifts should take around 30 minutes. Hit upper body one day, lower body the next day and do a full body strength day on the third day. On that third day you could try strength exercises that get the body moving....stairs, buddy carries, monkey jumps, partner exercises, towel pull-ups, etc. People have mentioned the pros and cons of doing this before or after practice. I would consider separating it entirely. See if you can get your coach to open up the weight room in the mornings before school. I liked Tues - Thurs mornings and - Sat/Sun afternoon. Lift throughout the season. Try to work around match days but also keep in mind what the goal is - State tournament. Get yourself where you need to be by the end of the season. Cut your lifting off a week before the state tournament.
There are other ways to do this and other philosophies. It depends on the kid, the coach, the school, the schedule, etc. Try to find someone who knows what they are talking about, who knows the sport, and preferably who knows the athlete.