Last night, the Red Sox started Pablo Sandoval at third base, the first time in four games he’d been in the starting line-up. He responded by singling to lead off the second inning and miraculously drew a walk in the third inning, which should tell you how sharp Jeremy Hellickson was last night. In the 8th inning, he was replaced by Josh Rutledge for defensive purposes, despite the fact that Rutledge has regularly graded out as one of the worst defensive infielders in baseball. But for Sandoval, this was a pretty successful night, reaching base twice and handling all four balls that he fielded.

But the fact that this is what constitutes a successful game for a player on a team trying to win is why the Red Sox should realize it’s time to just move on.

John Farrell has already acknowledged that Sandoval isn’t really the team’s starting third baseman anymore. His inability to hit left-handers means he’ll never start when a left-handed pitcher is on the mound for the opponent, and his struggles in the field make Farrell hesitant to start Sandoval when the Red Sox start a left-handed pitcher either, given that the opponents will have a lot of right-handed hitters pulling groundballs to the left side. So Sandoval’s current role is facing right-handed pitching when the Red Sox also happen to be throwing a right-handed starter, before being lifted for a pinch-hitter or defensive replacement when necessary.

Carrying a guy who can only play in very specific situations can work if the player is productive enough in those spots; lefty specialist relievers also have very narrow usage requirements, of course. But here’s the thing; 100 plate appearances into 2017, and it’s not clear that Sandoval can still hit right-handed pitching either.

During his time in San Francisco, Sandoval had a pretty basic offensive skillset; he offset an overly aggressive approach at the plate with good contact skills, and with roughly average power, he was an average-to-above-average hitter. That skillset mostly carried over in 2015, his first year in Boston, except he ran a .270 BABIP, and without enough power to compensate, that sank his overall offensive numbers.

Then he missed all of last year with a shoulder injury. This year, in the hoped-for rebound, he’s hitting .217/.277/.370 through his first 101 plate appearances. Of course, anyone can run a bad line for 100 PAs, especially with a .239 BABIP. But if you look under the hood a bit more, Sandoval’s core skill seems to be eroding.

Sandoval’s contact rates, both in and out of the zone, have sunk this year — you can ignore the 2016 marks on that graph, as he only hit seven times last year — and have led to Sandoval running a strikeout rate close to league average for the first time in his career. His overall 74% contact rate is eight percentage points below his career average. Some of that is just the fact that strikeouts have gone up league wide over the last few years, but most of it is Sandoval just swinging and missing with more frequency than he has before.

And Pablo Sandoval, with a league average strikeout rate, is just not a good hitter. He still swings at everything — he has the fifth-highest O-Swing% of any hitter with 100+ plate appearances — and allows pitchers to get him out on pitches out of the zone. Only 38% of the pitches he’s been thrown this year have been strikes, the lowest rate in the majors, so Sandoval is currently swinging at balls and swinging through strikes. That is a bad combination.

And Sandoval isn’t really trading contact for power. His .152 ISO is up slightly from his 2013-2015 stretch, but it’s below his career average, and league ISO as a whole is up now that everyone can hit home runs. Sandoval has launched four homers himself, and his exit velocity on fly balls shows that he can still hit the ball hard occasionally, but he hasn’t learned to avoid hitting ground balls yet, and in this day and age of shifting, a slow left-handed groundball machine isn’t a good thing to be.

In San Francisco, before every team started shifting on nearly every play, Sandoval was reasonably effective when hitting grounders, hitting .261 with a .282 SLG on GBs. Since arriving in Boston and having to adjust to life without the ability to pull the ball between the first and second baseman for a single, he’s hitting .188 with a .197 SLG. Without enough power to offset the GB-heavy batted ball profile, Sandoval is probably going to struggle to run a BABIP over .300 again.

He’s not a .239 true talent BABIP guy, but looking at his Statcast data, Andrew Perpetua’s xSTATS put him at a .271 xBABIP, in line with what he put up in 2015. He just doesn’t have the kind of batted ball profile or authority to be a high BABIP guy in the day and age of shifting, especially given that he hits more infield flies than you’d like to see.

So, taken together, Sandoval now looks like he’s going to run below-average BABIPs and his contact skills look to be eroding. If you take those things away, there’s not much left. Even with ZIPS and Steamer projecting close to .300 BABIPs for him going forward, he still projects to just a 91 wRC+ over the rest of the season, and once you account for the shift’s impact on his grounders, he’s probably not even likely to be able to match that.

That leaves him as something like an 75-85 wRC+ guy who can’t hit lefties and can’t play the field. And that’s just not a player a contender can afford to roster. I know the Red Sox don’t want to pay Sandoval $50 million to go away, and it’s easy to talk yourself into hoping that a guy with a big contract will come around and help the team, but Sandoval is the most glaring example in baseball of a sunk cost.

He has no trade value, and is not likely to ever be someone the team could move for any real return. Sandoval’s presence on the roster is solely about whether he can help the team win, and right now, the answer looks to be mostly no. A guy who can’t field and probably can’t hit much just shouldn’t be taking up a spot on a team trying to win.

Back in May, I made the case for calling up Rafael Devers, though he went into a tailspin immediately after that post went up. But he’s bounced back in June, hitting .372/.413/.721 this month, and still looks like he could be a superior internal option if the team wanted a left-handed third baseman to split time with Rutledge. Dave Dombrowski said this week that the organization doesn’t feel Devers is quite ready yet, but some of that probably involves the team not yet making the decision that it’s time to cut Sandoval and give his roster spot to someone more useful.

They should be there, though. Sandoval looks like a below-replacement level player, and the Red Sox simply shouldn’t be wasting at-bats hoping he remembers how to make contact or figures out how to beat the shift. Simply put, the Pablo Sandoval experiment failed, and it’s not going to be any more successful by letting him get at-bats that could go to a better player. If they don’t think Devers is going to be ready this year, then you make a trade for someone who is, because the AL East is the most competitive division in baseball, and the Red Sox are throwing at-bats and innings away on a guy who probably isn’t a big leaguer anymore.