Cregg was signed in October and, after a slow start, has been putting in some impressive performances in the middle of the park. The new contract is not a surprise, especially with Hugh Murray's injury, and means he'll be here until the summer at least.
The midfielder was let go by Hibs in the summer and spent several months without a club before coming to Saints. So desperate was he that he even considered signing for Morton, but fortunately those days are now behind him. Let's hope he continues to put in some good performances between now and the summer.
Story source: The Official St. Mirren Website