Unfortunately, most athlete photos are copyrighted. Remember, most photographers are making a living by selling the rights to print their photos in sports magazines and online papers, so if you take their photos without permission or payment, then they can't make a living.
I've had to get creative with fan sports pages. Here's what I use:
(1) Amazon products featuring baseball cards, posters of the athlete, or other images. (Sometimes I'll use the jersey/uniform.) (2) Use Flickr's advanced search and scroll all the way down. Check Creative Commons search AND the "commercial use" checkbox. Now and then a sports fan will generously snap a photo in a game and grant permission for commercial reuse. (3) Check Wikipedia's entry on the athelete. If there's a photo of him/her, click the photo and look below it to see what the usage and permissions are. But be careful, anyone can upload a photo to Wikipedia and not everyone understands copyright.
Sports is big business, and unfortunately, team logos and athlete photos have copyrights or trademarks or usage rights. If you're reporting on a news item, Fair Use may allow you to use a team logo, and practically speaking, teams usually won't come after a fan page or blog for featuring their logo (but you're pushing it). When it comes to photos by photographers, however, most photographers want/need to get paid.
It's a pain. But there's usually a workaround.
Question to experienced Hubbers: Is it possible to use Allposters.com affiliate images on Hubpages? That's a very useful, legal source of athlete and celeb images, as long as you're willing to be an affiliate and include the "Buy on AllPosters" link they give you below the image.