If an enlisted U.S. Navy SEAL becomes an Officer, would they have to go through the training pipeline again?

For example, if a Petty Officer Third Class in the U.S. Navy SEALs has earned a Bachelor's Degree and goes to Officer Candidate School to be commissioned an Ensign, would he have to go to SEAL training once again, or would he be able to return to the Navy SEALs, as he has already completed the training?