Dubravka played against Manchester United when Newcastle held the Red Devils to a 1-1 draw at St James' Park on 27 December 2021
Red Devils boss Erik ten Hag has been trying to get back-up for number one David de Gea following Dean Henderson's loan move to Nottingham Forest.
Attempts to sign Eintracht Frankfurt's Kevin Trapp failed when the German opted to stay in the Bundesliga.
Ten Hag has now turned his attentions to Slovakia keeper Dubravka, 33, who moved to Newcastle in 2018.
Although Dubravka was a regular in the Premier League last season, he has lost his place to new Magpies signing Nick Pope.
United have already signed Christian Eriksen, Casemiro, Tyrell Malacia and Lisandro Martinez this summer.
-- Courtesy of BBC Sport