Now that Neil Walker has taken his talents to Milwaukee, the Mets have some decisions to make about next season.

With the team’s incumbent second baseman gone, the Mets have no clear-cut choice to play second base on Opening Day in 2018. There are a few internal options, a few external options, and a whole lot of uncertainty surrounding the keystone position.

In the immediate future, it looks as though Jose Reyes will be taking over at second, with Asdrubal Cabrera and Wilmer Flores playing third while T.J. Rivera is out of commission. With Reyes up for free agency and Cabrera possibly leaving too, it’s safe to say the Mets’ 2018 starting second baseman will not be Jose Reyes.

The Mets have a couple of internal options to cover second: They could put T.J. Rivera there, although he seems to be the top contender for third base next season. He’s been a fantastic hitter when healthy, batting .304/.335/.445 in 106 career MLB games. If the Mets end up filling third base with someone from outside of the organization, Rivera could be a good choice to play second.

Another internal option would be Wilmer Flores. Flores has played 88 career games at second base and while he’s proven to be a solid utility infielder, he has yet to prove he can be a solid everyday player defensively. This means that Flores will probably continue to be a regular part-time player again in 2018 rather than a full-time second baseman.

Internal option No. 3 is contingent on the Mets deciding what to do with his option. Asdrubal Cabrera has played third base since being moved off of shortstop, save for a short period at second. He demanded a trade after being moved to second base in July, but has since backed off of that demand.

Cabrera has an $8.5 million team option for next season, and the Mets are reportedly weighing whether they should pick that up or not. If they do, we could see some combination of Rivera and Cabrera at second and third, probably the most likely scenario. You’d like to do better than Cabrera, but $8.5 million isn’t the worst price for a starting second baseman– and as we saw last week with the Jay Bruce trade, the Mets still care an awful lot about price.

The last internal option, unlike the other three choices, has very limited Major League experience. Gavin Cecchini could win the starting second base job out of spring training, but the difficulty of that task will of course depend on how many suitors there are for the position.

Cecchini, 23, is 6-for-20 (.300) in his MLB career, and has hit an impressive .283/.348/.395 across six minor league seasons. He is not known for his power, however he does have one Major League home run – which he hit off Clayton Kershaw. Cecchini is a Mets prospect, and if he impresses enough between now and next March, he would certainly be a serious contender for the 2018 second baseman job.

The second base free-agent crop this offseason is actually pretty slim. It’s led by, you guessed it – Neil Walker. The Mets could opt to bring back Walker, whose market has reportedly been hampered by the hamstring injury he suffered earlier this season. This could make for a deal that’s both shorter-term and cheaper.

Another option that could make more sense is Brandon Phillips, who is batting a solid .285/.328/.423 for the Braves this season. At 36, he probably won’t net more than a two-year contract. It’s worth noting that Phillips had a 35-game hitting streak in Flushing snapped this season which dated back to the Mets’ Shea Stadium days. Other free-agent second basemen include Jed Lowrie, Stephen Drew and Chase Utley, though it’s safe to say the Mets won’t be signing Utley.

So who will be the Mets’ second baseman in 2018? It depends largely on how Rivera, Flores and Cabrera play the rest of this season, as well as how much the front office is willing to spend between November and March.