Without trying to sound offensive, the most exciting players in this year's free agent class of offensive players are backups. Trent Dilfer is the best free agent quarterback, but he has started the past two seasons a backup.

	Antowain Smith had a breakout year with the Patriots, rushing for 1,157 yards in the regular season.

Az-Zahir Hakim is an instant offensive threat that fits perfectly into Chiefs coach Dick Vermeil's plans to recapture the excitement he enjoyed in St. Louis. But Hakim is a backup. The Chargers gave backup wide receiver Tim Dwight a five-year, $15 million deal that other receivers in this market will have trouble topping, and he's a backup.

Even the best running backs available in free agency are having to escape the recent tags of being backups. Antowain Smith is hoping his Super Bowl fling in New England will erase memories of being a backup in Buffalo. New Tampa Bay Buccaneers coach Jon Gruden has to figure out if free agent halfback Warrick Dunn is the starter or the backup behind Mike Alstott.

Can distinguished veteran backs such as Garrison Hearst, Ricky Watters and Terry Allen find homes with decent pay?

Team won't be overly aggressive in pursuing this year's crop of free agent offensive players. Only five of the unrestricted free agent receivers -- Donald Hayes in Carolina, Bill Schroeder in Green Bay, Willie Jackson in New Orleans, Michael Westbrook in Washington and Jacquez Green in Tampa Bay -- started last season.

The most interesting free agent is Germane Crowell of the Lions, who is coming off a knee injury. Crowell has 80-catch potential.

The tight end market is enhanced by the recent releases of Ken Dilger of the Colts and Freddie Jones of the Chargers. The Vikings are trying to re-sign Pro Bowl tight end Byron Chamberlain, but he should entice some bidders. Stephen Alexander of the Redskins is the best young talent on the free agent market, but he is coming off an injury-plagued season.

Many of the top backs would like to stay with their own teams. The Patriots want Antowain Smith. The 49ers would like to find a way to keep Hearst. Dunn's chances of staying in Tampa Bay depend on playing time more than money. Dunn wants to be the featured back. Michael Pittman of the Cardinals is an interesting case because he is a powerful inside runner.

The luster was taken out of the offensive line class when Walter Jones of the Seahawks, Tarik Glenn of the Colts and Flozell Adams of the Cowboys were franchised and Jason Fabini signed a five-year, $18 million deal with the Jets. How thin is the left tackle crop? Todd Fordham, Spencer Folau and Trey Teague are the top left tackles. Bears center Olin Kreutz should be able to grab a $4 million a year contract from the Bears or another team. The 49ers are fighting to keep center Jeremy Newberry, their best lineman last year, from hitting the market. Victor Riley of the Chiefs and Todd Weiner of the Seahawks could do well in the right tackle market.

The deepest position on offense will be where there is the least negotiating clout. Ron Stone of the Giants, Steve McKinney of the Colts, Chris Naeole of the Saints and DeMingo Graham of the Chargers head an impressive group of guards, but the salary cap will keep their values under $3 million a year.

John Clayton is an ESPN.com senior writer.