When the Toronto Blue Jays signed Jarrod Saltalamacchia on Tuesday, they arguably locked in their lineup and bench for 2017.

There will be a batting order to decide, there’s a chance one of their young catchers could break through, and the health of Devon Travis tends to be an open question, but the team has 13 position players under contract and is ready to start the season as constructed on the offensive side of the ball.

However, for all that stability, the Blue Jays have themselves one rather noticeable gap in their offence: left field. Ezequiel Carrera, Melvin Upton Jr., and Steve Pearce can all play the position, but they are three pieces that simply don’t fit together in a logical way.

Whenever a team has multiple players slated to play a single position, the word “platoon” finds it’s way into the discussion – and for good reason. Platooning a left-handed hitter and a right-hander is a good way to get the best possible production out of both parties. It’s a simple yet beautiful two-ingredient concoction, like a peanut butter and jelly sandwich.

Unfortunately for the Blue Jays, they don’t have the right ingredients. In Upton, Pearce, and Carrera, the Blue Jays have themselves a peanut butter, peanut butter, and mustard sandwich. Both Upton and Pearce are accomplished lefty mashers who can handle their end of a platoon masterfully. The former provides more defensively, the latter is a better hitter, but either one is a natural fit. With the way the Blue Jays roster is put together, Pearce is likely to be needed at first base against southpaws and Upton is probably the man in left.

The problem lies with Carrera. The 29-year-old certainly has his uses as a versatile defender, accomplished bunter, and swift runner, but he is not fit to carry the strong side of a platoon.

Carrera has stepped to the plate 646 times against right-handers in his career and hit just .245/.304/.345. Last year, he slashed an even-worse .218/.307/.320, so it’s not as if he’s made any recent adjustments. Unless you’re playing left field like Alex Gordon circa 2014, that won’t fly for the 100-plus starts demanded of the left-handed side of a platoon.

View photos Blue Jays outfielder Ezequiel Carrera struggling during the second half last season, hitting .194 with 34 strikeouts in 33 games.(Getty Images) More

As it happens, deep into January there’s a free agent out there who fits the Blue Jays need here to a tee, and his name is Chris Coghlan. The 31-year-old is coming off a down season in 2016, but represents the ideal platoon partner for Upton.

Last year, Coghlan got off to an unbelievably poor start, hitting .146/.215/.272 with the Oakland Athletics. But then his former team, the Chicago Cubs, scooped him up and he hit .252/.391/.388 down the stretch for the World Series winners. Given his track record, it’s fair to expect something more like the latter than the former going forward. Even Steamer’s relatively-conservative .244/.327/.388 projection for him in 2017 is far better than what the Blue Jays could expect to get from Carrera.

For his duration of his career to this point, Coghlan has been built for the platoon life. He hits right-handers well (.766 OPS) and southpaws very poorly (.620 OPS). He plays multiple positions – left field, third base, and second base – but none of them well enough that sticking him in the lineup every day is a must. He’s no one’s idea of a saviour – or even an everyday player – but as a solid left-handed bat who doesn’t embarrass himself in left field he’s precisely the piece the Blue Jays need.

The most difficult part of a potential Coghlan signing is that it would come at the expense of Carrera’s roster spot. With Upton as a platoon partner/fourth outfielder, there simply couldn’t be a place on the active roster for the Dominican speedster. Finding a taker for Carrera and his affordable $1,162,500 contract wouldn’t be too onerous a task, but it would be a tough one for many Blue Jays fans to swallow.

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