Chris Chambers and Marty Booker today become the first Dolphins receiver tandem to start four consecutive season openers since Mark Clayton and Mark Duper in the 1980s. And their personal stakes have never been higher. Both have big 2008 cap numbers ($7 million for Chambers, $5.2 million for Booker). Both have ascending young players behind them ( Ted Ginn Jr., Derek Hagan). And both have been mentioned in trade rumors, with Miami denying a report that Chambers has been shopped (NFL Network's Adam Schefter insists otherwise), but not denying that Booker was shopped (those reports were true). With the Dolphins coveting young, fast, explosive receivers, both must convince Cam Cameron they are worth keeping long-term. The Dolphins' starting receivers averaged a league-low 6.7 yards per pass attempt in '06, although the quarterbacks deserve lots of blame. ''You have an older receiver in Booker [31], and Chambers hasn't really shown up [last year],'' ESPN analyst and former receiver Keyshawn Johnson said. Chambers, 29, has said he won't ''let happen again'' what occurred in 2006, when his yards dropped to a career-low 677 (on 59 receptions) after a career-high 1,118 (82 catches) in 2005. ''It was deflating,'' he said, confident he will top last season's four touchdown catches. Although Miami values Chambers, his drops (14 last year) concern at least one team executive.