Williams, 19, played the full duration of last week’s 7-2 Carabao Cup third-round win at Lincoln and lost possession in the build-up to the hosts scoring their first goal.
The Wales international received abuse on social media afterwards and the profile picture and background picture on his Twitter account have been blacked out.
Speaking ahead of Thursday’s fourth-round home clash with Arsenal, Lijnders said: “It is not for me to comment on social media.
“The only thing I can say is abuse is wrong – through social media, on the street, it is wrong. Second, you are not a Liverpool supporter if you don’t support.”
He added: “Trent (Alexander-Arnold) spoke with him (Williams), Virgil spoke with him, Robbo (Andrew Robertson) spoke with him – so it’s not only Jurgen or me.
“It’s how we take care of each other and that’s what makes us different.”
Lijnders had earlier said of Williams: “Neco is a doer, and doers make mistakes. We don’t want safe play, a player who doesn’t take risks. Our game is based on everyone taking the initiative from each position, and that is what we want.
“One of the most important lessons for each young boy who is coming through, each player, is that it is a weakness if you can get caught up in praise and criticism. I think he dealt with it really well, to be honest.”
Another 19-year-old Lijnders spoke about on Wednesday was Reds midfielder Curtis Jones, who scored twice in the Lincoln game.
Jones converted the winning penalty when Liverpool played Arsenal at home in the Carabao Cup fourth round last season – a 5-4 victory on penalties after a chaotic 5-5 draw – and has made impressive progress since.
Lijnders, who has described Jones as “probably the most offensive midfielder we have”, said: “A banana skin is that a young player wants to go too early, too soon.
“I think the way we balance it and the way we give at the right moments, on the right timings with the right players around, the opportunities, that creates unbelievable processes that we saw last year. Curtis is a good example of that.”
Liverpool host Arsenal again three days on from beating them 3-1 at Anfield in the Premier League.
Thiago Alcantara, not involved in the last two games, is unavailable after testing positive for coronavirus and skipper Jordan Henderson (knock) will also not feature.
Kostas Tsimikas (thigh), Joel Matip and Alex Oxlade-Chamberlain (knee) are all out of action because of injury as well. Seventeen-year-old defender Billy Koumetio will have his fitness checked ahead of a potential first-team debut, and it remains to be seen if Rhian Brewster is part of the matchday squad as he continues to be linked with a move.
