Lions send tight end Dan Gronkowski to Denver in exchange for cornerback Alphonso Smith

The Denver Broncos have parlayed their depth at defensive back into plugging a huge hole at tight end.

The Broncos traded cornerback Alphonso Smith to the Detroit Lions on Saturday for Dan Gronkowski in a swap of second-year players who have yet to make an impact in the NFL.

Although Gronkowski had just one catch for 4 yards in two games last season, at 6-foot-6 and 255 pounds he represents a bigger target for Broncos quarterbacks and he did catch seven passes for 80 yards in the Lions preseason.

Tight end surfaced as a priority for the Broncos this summer and became a critical need when Marquez Branson, who was released Saturday, suffered a knee injury in Denver's preseason finale. Neither Daniel Graham (ribs) nor Richard Quinn (leg) has been able to stay healthy, either.

Gronkowski will be asked to fill the role that Tony Scheffler played last year before he had a falling out with coach Josh McDaniels and was dealt to Detroit in the spring.

Gronkowski was a seventh-round pick by Detroit out of the University of Maryland last season.

Smith had a bad rookie season last year after the Broncos traded a 2010 first-round pick to Seattle to move up and select him out of Wake Forest in the second round.

He never made enough headway in the defensive backfield to do much from scrimmage and his rookie contributions were limited to special teams, where he returned 10 punts for 47 yards.

The Broncos also placed NFL sack leader Elvis Dumervil (chest muscle) and wide receiver Brandon Stokley (groin) on injured reserve Saturday, officially ending their seasons, and they put defensive lineman Ben Garland from Air Force on their reserve/military list.

Denver also cut 10 players, including defensive end Jarvis Green, who is owed $3.255 million from the Broncos this season. Green received a four-year contract worth nearly $12 million that included a $2.5 million signing bonus last spring.

He was one of three beefier defensive linemen that the Broncos signed in free agency, along with Jamal Williams and Justin Bannan, but he couldn't unseat Ryan McBean.

Darrell Reid, an outside linebacker and special teamer who had four sacks last season, also was jettisoned. He's still recovering from offseason knee surgery.

The Broncos also released linebackers Kevin Alexander and Worrell Williams along with wide receiver Britt Davis, tight end Riar Greer, safety Kyle McCarthy, defensive lineman Jeff Stehle and offensive lineman Seth Olsen, a fourth-round pick out of Iowa last year.