Start up a quick play game on Rookie difficulty. I found that the best team for this was the San Francisco 49ers. They have Patrick Willis (linebacker) and he is a monster on defense. You can play against any team of your wishing.
This trophy thankfully can be unlocked by just forcing 3 fumbles in one game. So it doesn't matter if you recover any fumbles. It also doesn't matter if the 3 fumbles are caused by 3 different players. But Patrick Willis is a "big hitter" and he alone caused 2 of the 3 fumbles I needed.
This trophy will pop at the end of the game!