Opinion of Advocate General Campos Sánchez-Bordona delivered on 8 May 2019.#Delta Antrepriză de Construcţii şi Montaj 93 SA v Compania Naţională de Administrare a Infrastructurii Rutiere SA.#Request for a preliminary ruling from the Curtea de Apel Bucureşti.#Reference for a preliminary ruling — Public Procurement — Public procurement procedure — Directive 2014/24/EU — Article 57(4) — Optional grounds for exclusion — Exclusion of an economic operator from participating in a public procurement procedure — Early termination of a prior contract on account of partial subcontracting — Concept of ‘significant or persistent deficiencies’