SEATTLE -- The Mariners completed one of their better seasons in franchise history Sunday, finishing with the sixth-most wins in the team's 42-year history. Yet a frustrating second-half slide and missed playoff opportunity raises a multitude of offseason questions.
As manager Scott Servais summarized: "We did a lot of good things. We didn't do enough."
Here are five of the bigger issues facing general manager Jerry Dipoto and his staff as they contemplate what to do now with a club that went 89-73, but was still nine games behind the A's for the American League's No. 2 Wild Card berth.
1. Stick with the plan, or is change afoot?
One of the main orders of business will be deciding how real this year's success was, and if the team is legitimately capable of competing for a postseason berth next season by continuing down a similar path of trying to build around the current core.
The surprising first half was largely a function of winning the most one-run games in the Majors, including a number of dramatic walkoffs and comebacks. Part of that was due to Edwin Diaz's remarkable success rate as a closer, but there also is an element of luck involved in winning so many close games. The second-half struggles were at least partially due to expected regression for a club whose run-differential indicated it had played over its head in the first half.

Seattle finished with a run differential on the season of minus-34. Compare that to the Astros' plus-263. Or Oakland's plus-139. Or even the Angels at minus-1 with a team that went 80-82.
Dipoto has been baseball's biggest tinkerer in his first three seasons in Seattle, but he hasn't made a lot of blockbuster deals, focusing instead on building up the roster around the now-aging core of Felix Hernandez, Robinson Cano, Nelson Cruz and Kyle Seager.
Change clearly is coming and this year's club relied far less on that core. But the question is whether the Mariners think they're close enough to competing again for a playoff berth to hold off on a major shift in thinking and how to deal with the amount of money being spent on those players.
2. Where do all the puzzle pieces fit?
Cruz is the Mariners' biggest pending free agent and they'd love to bring him back, but the current roster wound up with an awkward fit of position players after Cano returned from his 80-game suspension. Dee Gordon clearly is more comfortable as an infielder, but Cano is much better at second base than first. And if Cruz is re-signed as a designated hitter, it'll be largely the same issue again next season. Depth and options are good, unless it means forcing key players into positions that lessen their value.

A decision needs to be made as to whether Gordon is the permanent center fielder. If not, center field would be the prime need in free agency or via the offseason trade market. If Cruz returns at DH and Cano plays second base, could Gordon shift to shortstop and make Segura a potential trade chip? Is Ryon Healy the long-term solution at first? And can Seager bounce back from the most frustrating season of his career?
Dipoto is a solution-maker, but he'll be challenged more than ever this offseason.
3. Does that rotation need help now?
Hernandez and his remaining one-year, $27-million contract need to be resolved as he comes off an 8-14, 5.55 ERA season. The Mariners got 25-plus starts from all five of their primary starters this year after an injury-riddled 2017 turned into a pitching merry-go-round.
Thanks to that stability, the Mariners rotation fared much better than most people expected after Dipoto stood pat with his returning group last winter. The one exception was Hernandez. The Mariners were 69-46 in games started by James Paxton, Marco Gonzales, Mike Leake or Wade LeBlanc, but 11-17 in Hernandez's outings.
It would be a large leap of faith to expect Hernandez to bounce back next year, or for the Mariners to go through another season with no significant injuries to their starting five. Seattle doesn't have a young Major League-ready starting prospect in its system, so this seems a likely target for Dipoto.
4. Is it time to restock the farm?
As noted, there aren't any young starting pitchers in the immediate pipeline. In fact, none of Seattle's top prospects are yet knocking on the door. Additionally, only four rookies were on the Mariners' 38-man Major League roster in September -- first baseman Daniel Vogelbach, catcher David Freitas and relievers Matt Festa and Nick Rumbelow.
Dipoto has done a nice job making Seattle's Major League core younger with the additions of Mitch Haniger, Segura, Healy and Gonzales, but the next wave of help from top prospects like Kyle Lewis, Evan White and Logan Gilbert -- the team's last three first-round Draft picks -- remains at least another year or two away.
The Mariners only have a small group of players -- Diaz, Haniger, Paxton and perhaps Segura -- whose age and contract status would bring back quality younger prospects. And giving up those players would mean taking a significant step back now.
5. Does the chemistry need to be re-mixed?
The Mariners seemed to be one big happy family for much of the season when things were going well. But as often happens, things got a little rocky when the ship took on water and once-promising playoff hopes disappeared.
Chemistry and its importance are often difficult to judge, but it would be impossible to ignore the clubhouse fight that broke out between Gordon and Segura late in the season, as well as lingering frustration among some toward Segura after he pulled himself out of a crucial series in Oakland in late August for two games with a bruised shin.
Servais benched Segura for not running the bases hard Friday, another sign that things aren't all roses. The Mariners will likely downplay any personnel issues, but it'll be interesting to see if Dipoto feels the need to make moves this winter to clear the air as well as clarify some of the roles for his returners.