Tiki Barber has decided to return to professional football. When he left the league he was a member of the New York Giants. Before he can be eligible to compete with another team, he must be released by the Giants.
Similarly, in college athletics, if you leave one university to attend another university you must receive permission from the first university BEFORE you can speak with the second university about transferring. This is true even if you did not compete at the first university.
For more information on the NCAA Transfer Process read NCAA Transfer Student-Athletes: How to Transfer Schools and Still Be Eligible to Compete and How to Transfer from a Two- Year College to an NCAA School and be able to Compete.