Complex sentence: Szetela opted not to continue a career in Europe and returned back to the States and signed a contract with Major League Soccer and was signed selected by D.C. United, who were second in the allocation placements to sign returning U.S. international players.
Split into simpler sentences: Szetela opted not to continue a career in Europe and returned back to the States and signed a contract with Major League Soccer. His contract was picked up by D.C. United, who were second in the allocation placements to sign returning U.S. international players.