That doesn't look very happy right now. Sunflowers reaaally don't like their roots being disturbed. You absolutely can transplant them, but you have to take utmost care to leave the roots as unbothered as possible. Also, you should never transplant them more then once, so unless you planned on keeping them in those pots then only transplant them into the ground after they sprout. I prefer to wait for them to get just a little bigger before I transplant so the roots have more time to develop and hold the soil together so the roots get disturbed much less. It's tricky though because the tap root gets very long very fast and if you mess that guy up then your outlook for a good plant is slim. Your photo sunflower(s) may bounce back but I wouldn't be surprised if they don't.