The Mets continued their offseason of low-level acquisitions by agreeing to terms on a one-year, $4.5-million contract with lefthanded-hitting outfielder Alejandro De Aza, a baseball source confirmed Tuesday.

De Aza, 31, spent 2015 with three teams — Baltimore, Boston and San Francisco — and hit .262 with seven home runs and 35 RBIs. He is expected to serve as a complement to Juan Lagares once the contract is finalized following a physical.

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De Aza is not considered a top defensive centerfielder — he played only eight innings at the position last season — and likely will be the junior partner there rather than face every righthander as part of a platoon. The Mets still have hopes that Lagares, who won a Gold Glove in 2014, can re-emerge as an everyday player. That means he would have to show he can hit righthanders. De Aza is a hedge if he can’t.

The Mets continued their pattern of staying away from big-money outfielders, including their own free agent Yoenis Cespedes. The market for free-agent outfielders has been slow to develop since Jason Heyward signed his eight-year, $184-million contract with the Cubs.

Cespedes, Justin Upton, Alex Gordon and Chris Davis (a first baseman who can play the outfield) are still free agents, but the Mets feel set at the corners with Michael Conforto and Curtis Granderson. To date, they have not wanted to make the nine-figure commitment it probably would take to re-sign Cespedes, who would have to play center for at least the first two years.

So, unless something unexpected happens, the Mets will finish their offseason by continuing to look for middle-relief help — Tyler Clippard is still unsigned — and a righthanded-hitting outfielder to replace the retired Michael Cuddyer.