Bob Dutton

Bob Dutton

   SEATTLE — There’s no getting around it. Losing perennial All-Star second baseman Robinson Cano, for however long, creates a cavern in the middle of the Mariners’ lineup.

   Cano suffered a broken bone in the pinky finger of his right hand Sunday when hit by a pitch from Detroit lefty Blaine Hardy. The early guess is Cano will be sidelined for weeks and perhaps months.

   The Mariners have no good replacement options. (What club would?) It probably means more playing time for utilityman Andrew Romine with Taylor Motter (or perhaps Gordon Beckham) being summoned from Triple-A Tacoma.

   UPDATED: The Mariners promoted Beckham prior to Monday's game at Minnesota after placing Cano on the disabled list. The move came one day before Beckham had the option of becoming a free agent if not on the big-league roster.

   Manager Scott Servais said the Mariners, at least initially, will stick to internal options, which makes sense. This year’s club is better built to absorb a major injury to their lineup than in previous years.

   The club previously weathered disabled-list stays for designated hitter Nelson Cruz, catcher Mike Zunino, first baseman Ryon Healy and outfielder Ben Gamel. Losing Cano will be the biggest test yet, but this remains a deep lineup.

   In fact, let’s get ahead of ourselves for a moment and make this assumption: The Mariners will be looking to bolster their roster when clubs begin to separate themselves into contenders and pretenders.

   That sorting process, and accompanying personnel moves, typically begins about a month from now and gathers steam as the calendar approaches the non-waiver trade deadline on July 31.

   Projecting the Mariners as buyers is just that, a projection, but this is a veteran club constructed to compete now. Even a key injury — like Cano’s broken hand — or a bad stretch of play isn’t likely to shift their focus.

   It’s tempting to look at the rotation’s 4.99 ERA through Sunday and see the need for an upgrade, but adding an impact starting pitcher during the season nearly always comes at an enormous cost in prospects.

   And that, effectively, puts the Mariners at a sharp disadvantage because their system lacks the ready-now, impact, upper-level prospects to execute such a deal.

   Even club officials acknowledge that targeting additional bullpen help is the more-likely option. In part, that’s because the price for relievers is much lower than starting pitchers. But there are also more of them, which depresses the market.

   Most important is the Mariners’ bullpen, a supposed strength entering the season, is currently throwing oil is all directions. Primary setup man Juan Nicasio melted down again in Sunday’s 5-4 walk-off loss to the Tigers and now sports a 6.16 ERA.

   The unit’s other primary right-hander setup man, Nick Vincent, has been better lately, which has his ERA down to 4.02, but lefty specialist Marc Rzepczynski has a 10.13 ERA in 13 appearances.

   While closer Edwin Diaz has been great, these Mariners, with their five-and-dive rotation, aren’t going anywhere with a leaky bullpen bridge to the ninth inning. They ought to be looking to add two relievers — a lefty and a righty.

   Wondering who might be available?

   It’s all guesswork at this point, but Jon Heyman of the Fan Rag Sports Network recently compiled a list of potential mid-season trade candidates that included six relievers among the top 17 possibilities.

   Let’s be clear: These are relievers who only MIGHT be available, and there’s NOTHING at this point to connect them to the Mariners. For now, we’re just gathering names — and this is not an all-inclusive list.

   Even so, take a look:

   ***Kansas City right-hander Kelvin Herrera has been lights out. He’s probably the best candidate on this list, but he’s a short-term fix since he’ll be a free agent after the season. He is making $7.9375 million.

   ***Baltimore lefty Zach Britton is still recovering from December surgery to repair a ruptured Achilles' tendon. He could be back in action by the end of the month. If he’s healthy, he’s dynamite. Britton had a 1.61 ERA in 242 games from 2014-17. He’s also a pending free agent — and a pricey one: He’s making $12 million.

   ***San Diego lefty Brad Hand, who is signed through 2020 with a club option for 2021. He’s making about $4 million this season but that jumps to a combined $15.5 million guarantee over the next two years.

   ***Cincinnati righty Raisel Iglesias continues to put up terrific numbers in a hitters’ ballpark. He is a Cuban defector whose original seven-year, $27 million deal is backloaded and runs through 2020.

   ***Baltimore right-hander Brad Brach is serving as the Orioles’ closer in Britton’s absence, but he’s struggling after a series of strong seasons — although his strikeout numbers remain superb. He is a pending free agent who is making $5.165 million.

   ***Tampa Bay righty Alex Colomes performance is down after leading the majors last season with 47 saves and compiling a 1.91 ERA in 2016. He is making $5.3 million and is under club control for two more years through arbitration.