Virgil van Dijk said Netherlands were below their best against Belarus, despite a 2-1 win in Minsk to close in on Euro 2020 qualification.
Central defender Van Dijk told Dutch broadcaster NOS: "The second half was, to put it mildly, not good. We lost the ball a lot in midfield after half-time, which allowed them to counter-attack. They weren't really dangerous, but we must do that better.
"We have to look at ourselves in the mirror. We all want to go to the Euros. The whole of the Netherlands is yearning for that, including the players of course. We are close, but we have to analyse the second-half performance and then finish the job in the next international break."
Despite concerns about the level of performance against Belarus, Van Dijk never thought Netherlands were in danger of losing their lead. He said: "It might have seemed dangerous, but I thought we had it under control."