It turns out that learning an NFL playbook isn't the easiest task in the world. Due to changing terminology and significantly more complexity than the college game, rookie players, and even many vets, struggle to learn a new playbook. It's something that takes time and effort.
Tajh Boyd confirmed this by stating, "It takes time. I've got to understand that, to be patient a little bit. But I'm doing everything I can so that I'm ready and I'm confident when I go on the field." Fortunately for Boyd, nobody is expecting him to see the field anytime soon. Boyd is currently locked in a gripping battle for the third quarterback spot with Matt Simms that, frankly, I expect him to win. Simms has a low ceiling, and while Boyd's may only be marginally higher, he's at least more athletic and at this point still has more potential.
You never want your third-string quarterback to see the field, and hopefully, Boyd will never have to. In the meantime, he can learn the playbook without being rushed into anything.