Wesley Sneijder was taken off as a precaution because of a sore ankle while Joris Mathijsen, who tweaked a hamstring in Saturday's 2-1 defeat by the Bulgarians, gave the camp a boost ahead of their Group B opener against Denmark on June 9.
"Sneijder had a sore ankle but he will be fine, while Wilfred Bouma had a head injury and visited a hospital for checks," coach Bert van Marwijk told reporters.
"Mathijsen is looking fine and according to the reports of our medical staff he might be recovered in time for the Denmark match."
During a lively opening five minutes both teams came close to scoring when Marek Hamsik hit the bar with a header before Nigel de Jong headed a corner-kick just wide.
A minute later, the Dutch opened the scoring when a fine cross from Ibrahim Afellay was deflected past his own goalkeeper by Kornel Salata.
Playmaker Sneijder was replaced by Rafael van der Vaart and the Tottenham Hotspur man scored the second in the 76th minute after Klaas-Jan Huntelaar had been stopped by two defenders.
"During big tournaments you will face opponents who will play like Slovakia today and I'm satisfied that we kept our patience the complete match where we lost it after an hour on Saturday," the coach added.
Netherlands will play their final warm-up on Saturday when they host Northern Ireland.
Germany and Portugal are their other Euro group opponents.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.