First let us start with the goal. Fifteen pounds in three weeks is five pounds per week. One pound is about 3500 calories. Therefore you would need a net deficit of 17,500 per week.
That is not insignificant.
I am all in on setting strong goals, but it reaches a point where it may be too aggressive without proper supervision. If like many reasonably active people you could do a 1000cal/hr exercise for 30 minutes you would have to do that exercise about 35 times per week, or 5 times per day every day for 3 weeks, assuming no reduction in calories consumed.
I'd put that as not very likely, no offense. The reality is as you increase effort you will increase your appetite. Adding 2.5 hours per day of intense exercise will lead to a concomitantly large appetite increase. Reducing calorie intake in such a situation will lead to problems unless under very close medical supervision.
That all said, now let us talk about strength training and weight loss. No, let us change it to fat loss. Do not go based on weight alone unless you are needing to meet specific weight barrier goals such as is found in wrestling, boxing, etc.. The reality is you should focus more on the makeup of the body, your composition.
So, let us say for sake of discussion you decided you wanted to drop 9 pounds of fat in 3 weeks, an aggressive but obtainable goal. First you will want to measure or have measured, your current body fat percentage. Second, take measurements. Measure your waist, belly, shoulders, legs, and perhaps arms even. Third, get someone to take a picture of you in clothing that is as revealing as you can be comfortable with. Now get rid of or hide your scale, you won't want to se fit for three weeks. Do all this preferably as soon as you get up but have not had breakfast.
This will serve as your baseline upon which to measure success.
Now you'll want a regimen that mixes cardio with strength training. Strength training has been shown time and time again to be a significant factor in fat loss. It stands to reason as muscle is what burns calories, the more muscle you have the more calories your body needs and thus the more fat burning potential you have. I would recommend lifting heavier weight with fewer repetitions two to three times per week. Cardio can be light on lifting days and a bit more intense on non-lifting days.
For cardio, don't waste your time doing long and slow. Go for Fartlek, or interval training. For example, find a treadmill and do 8 seconds as fast as you can followed by 12 seconds letting it run while your feet rest on the side. Do this for 20 minutes, or as long as you can to get to that point. At the end of the 20 minutes, you are done with it. Walk it down and call it good. Substitute this for your normal running but with less frequency.
Combine that with a sensible diet (I would recommend one which is protein rich, moderate fat, and low in carbs ) and you will shift your composition toward a more muscular and less fat one. The heavy weights with fewer reps will not make you bulky, but it will increase your strength. The interval training will help you with your speed on the field as well. Remember, people work very hard to get bulky - it doesn't happen by throwing some weights around. It takes dedication and very specific hard effort to get bulky on muscle (though it is easy to do with fat ;) ).
And regarding the post that cardio burns muscle, I say it depends on diet. Most people doing a lot of cardio do it "light and long", and don't get enough protein. You can do cardio with an appropriate protein intake and minimize muscle atrophy.
You can also do heavy cardio. Heavy cardio would be putting the treadmill at maximum incline and then doing your running. Another way is a bike machine set on high resistance. You use the same routine but by setting the resistance very high you stress the muscle much more than a light flywheel rotation routine.
Your diet as you relate it appears to be very high in carbohydrates. Shift that to the protein side and you'll see better benefits. You can cut out simple carbs such as grains and switch to vegetables and minimal fruit for your carbs and see better results. Also, for breakfast try to get 20-30g of protein in by the first hour after waking and you will see better fat loss.
Hope that helps. It may be a bit more than the title of your question asked as I tried to answer more of what you wrote in the question itself. After all the correct and simple answer to the title is "No.". :)