Free agents need moments. Juwan Thompson went undrafted and signed with the Broncos for $3,500. The minimal investment explains the urgency to capitalize on every chance. Thompson's arrived Thursday with 6:41 remaining in the second quarter of the Broncos' exhibition game with the Seattle Seahawks. From the shotgun, quarterback Brock Osweiler handed to Thompson, who motored around right end for 18 yards. "It took a long time for me to get into the game," said Thompson, his debut delayed by the 45-minute lightning stoppage. "Just like coach says, 'You've got to be ready to go. There's only one opportunity to play in the NFL.'^" Free agents need statistics. In the third quarter, with C.J. Anderson sidelined, Thompson rambled down the left sideline for 20 yards before the Seahawks' Tharold Simon slammed him head first to the ground. After clearing a concussion evaluation, Thompson returned, finishing his debut with team-high 59 yards on six carries. The guy you've never heard of is helping the Broncos resist the temptation to add a big name such as Felix Jones or Michael Bush to an injury-ravaged, inexperienced running back corps. With Anderson's status uncertain (concussion) for the Aug. 17 game at San Francisco and Montee Ball (appendectomy) out until at least the third preseason game, Thompson becomes an interesting option in the roster roulette.