This was supposed to be the easiest assignment of the year. Make the argument that Ryan Miller should be traded? OK. I’ve only been saying and writing that since the opening days of the season, so no problem.

Surprisingly, there has been a hiccup. The computer screen has sat blank, with just a lonely cursor blinking over and over.

It’s not a change of heart that has kept the words away. It’s that in order to make an argument, there has to be an actual argument. There isn’t one.

I’ve tried. The devil’s advocate hat fits snugly atop my head. But as hard as I scratch it, I just can’t for the life of me imagine why anyone would think the Sabres should keep Miller past the trade deadline and try to re-sign him.

The Sabres are multiple years and/or players away from being a legitimate Stanley Cup hopeful. Miller is about to enter the downside of his career. He hasn’t won a playoff series since George W. Bush was president. Though the Sabres have plenty of room under the salary cap, he’ll be too costly to re-sign in terms of value. Plus, the odds of doing it are slim. He appears ready to move on. The Sabres have stockpiled the crease organizationally, and with some luck and development they have his successor.

Put all that aside, and you’ve got … no reason to keep him.

There’s no doubt Miller is the most talented player on the roster. It’s not even close. He’s a really good goalie who can play at an elite level for long stretches. What has that gotten Buffalo? Last place and a whole bunch of no-shows in the seats on game nights. It’s hard to envision them being any good next year, either, no matter who is in the crease.

Next year is a huge one when it comes to Miller. There have been impressive, comprehensive studies done in regards to goaltenders and their careers. They’ve come to a similar conclusion: Age 34 is when goalies begin to fall off dramatically.

How old will Miller be when the puck drops next season? He’ll be 34.

Two studies, in particular, clearly define the rapid decline:

• Pension Plan Puppets, a site affiliated with SB Nation and dedicated to the Toronto Maple Leafs, studied the save percentage of 200 goaltenders who have played 60-plus games since 1984. It shows how a goalie who put up a .912 save percentage at age 30 (Miller was .916) drops to .905 at age 34, .899 at age 35 and .892 by age 37.

• Copper and Blue, another SB Nation site serving the Edmonton Oilers’ community, focused on whether goalies are starters, backups or out of the league as they age. Age 34 is when the majority become backups. At age 35, there are more retired goalies than backups or starters.

Does it make sense for a rebuilding team to offer multiple years and big dollars to someone who might not have much left?

There are, of course, goalies who seem ageless. Martin Brodeur, Dominik Hasek and Patrick Roy put up stellar seasons in their mid-30s.

But is Miller in their class? Or does he belong with stellar netminders such as Eddie Belfour, Tom Barrasso, Mike Richter, Miikka Kiprusoff, Olaf Kolzig and Grant Fuhr? I’d go with the latter. While they could stop breakaways in their prime, they couldn’t beat the odds that face aging goaltenders.

The Sabres don’t have a clear successor to Miller, but at least they have candidates. Jhonas Enroth has struggled, but countryman Linus Ullmark is a star in the Swedish elite league at age 20. Nathan Lieuwen is having a decent rookie season in Rochester. Cal Petersen, drafted last year, entered the weekend with a 23-2 record in the United States Hockey League.

By the time the Sabres are ready to compete, one of the goalies should be a legitimate NHL starter.

Though the aforementioned reasons should present a compelling case, a final one trumps them all. It looks like Miller is ready to go.

For insight into a player’s mind-set during the tumultuous last season of his contract, I talked with Brian Campbell in September. The former Buffalo defenseman gave a huge clue on what to look for with Miller and Thomas Vanek.

“It’s pretty easy if you don’t want to stay,” Campbell said. “Just go about your business and do your job and move on.”

Miller has simply gone about his business this season. The outbursts of emotion that have marked his tenure have been non-existent. He’s shrugged off the dips in the learning curve. He’s done his job, nothing more and nothing less.

Miller, whether he plays one more game in Buffalo or 100, will go down behind Hasek as the second-best goalie in Sabres history. That’s an impressive spot. But he’s shown plenty of signs the memorable run is over. It’s time for the organization to make it official.