It was no coincidence that the Dolphins' run defense gave up 150 of the Redskins' 191 yards in the second half and overtime when strong safety Yeremiah Bell was sidelined by what was initially described Sunday as a calf injury. On Monday, the news got worse. Bell actually suffered a season-ending torn left Achilles' tendon early in the third quarter while he was backpedaling. "He's a guy on our leadership group and had done everything to have a great year," coach Cam Cameron said Monday. "You thought letting a guy go was tough. This is the tough part of the business, where you sit down with a guy who has given you everything he's had and is a wonderful young man and now his season is over. Wasting no time, the Dolphins are bringing in veteran strong safety Donovin Darius for a workout today, according to a source. Darius, 32, known for his hard hitting (franchise-leading 846 tackles) during his nine years with the Jaguars, was cut by the Raiders last week and by Jacksonville last June.