The 36-year-old Elliott signed on a free transfer from Wellington Phoenix of the A-League. Boyens was with the New York Red Bulls, who did not renew his contract.
Elliott first played in MLS with the Los Angeles Galaxy from 1999-03, then was with Columbus from 2004-05. After a stint with England's Fulham from 2006-08, he played for San Jose in 2009 and then went to Wellington.
The 27-year-old Boyens was with Toronto in 2007, then spent three seasons with New York.