A player is perhaps least tradable when he's on one of the poles of his game -- at his best or at his worst. When he's at his best, up as his value may be, teams have trouble parting with him. And, of course, when he's at his worst, teams have trouble dealing him elsewhere.
This simple valuation certainly overlooks things like upside, injury and intangibles, but it nonetheless stands as a fairly good rule of thumb for trades.
Arizona Cardinals wide receiver Larry Fitzgerald is there -- at the south pole of performance, compiling the worst statistical nine-game start since his rookie season in 2004. And his struggles have elicited a peculiar response from some Cardinals fans. "Trade him," they say.
While a guest on The Dan Bickley Show with Vince Marotta on Friday, NFL.com reporter Ian Rapoport spoke about Fitzgerald's season and the potential of trading him elsewhere.
"I know he's not healthy," Rapoport began. "He still looks like the same guy. It's just, when you're a guy who runs for a living and you have hamstring issues, you're not going to get 100 percent, because he's just not fully healthy and he might not be this season."
As the reporter notes, Fitzgerald has had a nagging hamstring injury all season, something that has at times flared up so severely that the receiver's status for upcoming games was doubtful.
Naturally, then, the question of age has surfaced. Fitzgerald, 30, has had a generally healthy career, but his recent struggles seem a scary foreboding of his longevity in the league, though not for Rapoport.
"I don't think he's over the hill," he told Bickley and Marotta, "but it's obviously been an adjustment for him.
"I think he's still a great player, I think he's still a really talented player, you just haven't gotten everything from him just yet."
Given such a positive outlook on Fitzgerald's health, and general similarity in the look of his game, as Rapoport cites, perhaps the receiver is movable after all, as some fans might hope, despite his popularity and proven star potential.
On that prospect, the guest was quick to weigh in.
"It would be difficult because of the cap implications," Rapoport said. "It would be really hard to do."
Though going on to add that the idea wasn't completely far-fetched, Rapoport's pointing to Fitzgerald's contract is likely the key to the conversation. The 10-year-veteran is in the third year of a monster eight-year, $126 million contract. Finding a trading partner who has the cap space available to take on such an investment -- perhaps a deteriorating one -- will be the challenge for general manager Steve Keim and the Cardinals.
That aside, Rapoport went on to speak about Fitzgerald's meaning to the Cardinals franchise and the local community and how that, alone, adds to the quandary.
"If Arizona was even going to consider a trade," he explained, "then you're sending away the guy who's the face of the franchise, the leading receiver, so amazing in the community. If you were to even consider trading Larry Fitzgerald, there's a lot that goes into it."