"We've got a person coming in from outside who can give us a bit of a reality check, " Kafer said.

BBC: SPORT | Rugby Union | English | Saracens 18-22 Northampton

"We're aware of the events in Boston, " said Denver police spokesman Aaron Kafer, who declined to give specifics about security measures being taken.

NPR: Denver Pot Holiday Bringing Crowds, Tight Security

Sarries coach Rod Kafer is hopeful the arrival of assistant coach Steve Diamond from Sale will add some impetus to a Saracens side that lost yet again at home.

BBC: SPORT | Rugby Union | English | Saracens 18-22 Northampton