Urban areas can be conceptualized as large and ever-changing playgrounds in which many diverse agents (households, businesses, developers, municipalities, etc.) are active. The interactions between the playground qualities and the players' preferences are not unidirectional. However, sometimes, external events may change the perception of the playground qualities in the player's eyes. The recent Covid-19 pandemic and its associated precautionary measures are a clear example. During the pandemic, the value of existing urban green infrastructures has increased, as lockdowns were imposed, and distance working became widespread. The concept of "passive" ecological gentrification is developed in order to character-ize this type of process. In contrast with "active" ecological gentrification, caused by purposeful intervention in the urban arena, "passive" ecological gentrification is triggered by a change of context, such as the pandemic impacts. This article focuses on the appreciation of green urban infrastructures by urbanites during the pandemic, showing that the willing-ness to pay to live near green and open spaces has increased in general, but with significant spatial differences. The main research questions are (a) How does the player's perception of the playground's value change in times of pandemic? (b) Do these changes support the emergence of "passive" ecological gentrification? The methodology is based on the ana-lysis of changes in property values over time as an indirect measure of a location's appeal, looking specifically at areas near green urban infrastructures, both in the inner city and in the peripheral areas. Relatively large changes in property value over time are a possible indicator of ongoing gentrification processes When they are observed near existing green infrastructures, and not related to redevelopment initiatives, "passive" ecological gentrification may be the result. Using detailed spatial data on land use and property prices from the Netherlands, we find evidence that supports the hypothesis of a "passive" ecological gentrification drift towards areas around urban parks and green infrastructures in general.