Zack Martin is pretty much universally accepted as one of, if not the top guards in the NFL. But for the sake of argument, we are going to assume that Zack's Martin is the best guard in the NFL and we are going to also assume that from a football playing perspective that everyone wants us to keep him, which is almost universally true.
On the other hand, we have this thing called the salary cap. It's a hard cap that only allows you to spend so many dollars. That means that for every dollar you spend on Zack Martin you CANNOT spend that same dollar on anyone else. So if you pay Martin the biggest bucks in the league as a guard, then someone at another position is going to get slighted on salary.
Guard is not normally a top tier salary position and it's not a position that is normally drafted high. Granted that does seem to be changing, as Nelson was in the top 5 or so picks of this draft. But it isn't a position that on average gets paid as well as many other positions.
If we resign Martin, we are "probably" getting a player who can play out his full contract at a high level. I say probably because if he gets injured and can't return to elite form, a contract like we are hearing about can set this team back significantly in the cap department.
Contracts like this also can cause depth problems. We are finally getting some decent depth and this contract doesn't help that at all.
We could have easily traded Martin for a 1st. In fact we could have probably traded Martin for a first and more. Maybe even as much as a third.
The difference in pay between a first round rookie draft pick and the contract Martin will probably sign will be around $10 million dollars per year difference (times the length of his contract). So a 6 year deal would be a $60 million dollar difference in the total cap hit.
A draft pick is not likely to play at the same level as Martin, as Martin is a perennial pro bowler, but if the draft pick replacement at guard is a first round pick he should theoretically be a top tier guard. (Top 5 to 10 or better).
When you sign a player like this to a mega deal, all of the risk shifts over to the team. When a team signs a guy like this to a mega deal the BEST case scenario is that the player continues to play at a high level, justifies his cap hit, and maybe if the salary cap continues to go up you end up with a slight bargain in the last year or two of his contract. So best case, you get what you expected to get. But the worst case is a train wreck cap hit for an injured player or he underperforma his contract for whatever reason.
Here's what you didn't say was it doesn't matter what actual pick another guard goes, the list is a mile long of players as high as the 1st pick on down that were busts in the NFL. Also there aren't guards every draft of Martins caliber. Martin is a once a decade type guard and makes little sense to trade away (that word fans should take out of their vocabularies) a talent like that to 1) have him pay against the Cowboys and 2) knowing the chances are very slim of finding another guard as good as Martin in the draft.
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Granted I think Martin is a solid person so you minimize the intangible portion of the train wreck, but the injury part can't be under appreciated.
