Tim Sherwood was handed an 18-month contract in December last year following Andre Villa-Boas' departure.
However, Gullit has suggested it is a "done deal" for Van Gaal to take over when he leaves his current post after this summer's World Cup finals in Brazil.
The former Chelsea and Newcastle manager told BBC Radio Five: "I know for sure he was at Van Gaal's house, the chairman. I think it's a done deal, but you never know."
NEWCASTLE UNITED 2013/14
PREMIER LEAGUE
SOUTHAMPTON 4 NEWCASTLE 0
Elliot, Yanga-Mbiwa (45' Santon), Williamson, Coloccini, Haidara, Anita, Tiote, Ben Arfa (45' de Jong), Sissoko (78' Dummett), Gouffran, Cisse
Subs: Gosling, Shola Ameobi, S Taylor, Alnwick
NEWCASTLE 0 EVERTON 3
Krul, Yanga-Mbiwa (75' Marveaux), Williamson, Coloccini, Dummett, Sissoko, Anita, Tiote, Gouffran (90+1' Shola Ameobi), de Jong (58' Ben Arfa), Cisse
Subs: Gosling, Haidara, Elliot, S Taylor
NEWCASTLE 1 CRYSTAL PALACE 0 (Cisse)
Krul, Yanga-Mbiwa, Williamson, Coloccini, Dummett, Sissoko (88' Marveaux), Tiote, Anita, Gouffran (76' Shola Ameobi), de Jong (59' Ben Arfa), Cisse.
Subs: Gosling, Haidara, Elliot, S Taylor.
FULHAM 1 NEWCASTLE 0
Krul, Yanga-Mbiwa, Williamson, Coloccini, Dummett, Sissoko, Tiote, Anita (81' Marveaux), Gouffran, de Jong (86' Armstrong), Cisse (71' Shola Ameobi).
Subs: Gosling, Haidara, S Taylor, Alnwick
HULL CITY 1 NEWCASTLE 4
Krul, Debuchy, Williamson, Yanga-Mbiwa, Dummett, Sissoko, Tiote, Anita, Gouffran, de Jong (90' Gosling), Remy
Subs: Cisse, Haidara, Marveaux, Shola Ameobi, S Taylor, Alnwick
NEWCASTLE 1 ASTON VILLA 0 (Remy)
Krul, Debuchy, Williamson, Coloccini, Dummett, Sissoko, Cheick Tiote (89' Gosling), Anita, Gouffran, Remy, Cisse (72' de Jong).
Subs: Yanga-Mbiwa, Haidara, Elliot, Shola Ameobi, S Taylor
NEWCASTLE 0 SPURS 4
Krul, Debuchy, Williamson, S Taylor, Santon (45' Dummett), Anita, Sissoko, Gouffran, de Jong (63' Ben Arfa), Sammy Ameobi (71' Marveaux), Cisse
Subs: Yanga-Mbiwa, Gosling, Elliot, Shola Ameobi
CHELSEA 3 NEWCASTLE 0
Krul, Debuchy (40' Yanga-Mbiwa), Williamson, S Taylor, Dummett, Anita (84' Marveaux), Santon, Ben Arfa (64' Gosling), Sissoko, Sammy Ameobi, de Jong.
Subs: Haidara, Elliot, Shola Ameobi, Armstrong
NEWCASTLE 0 SUNDERLAND 3
Krul, Debuchy, Williamson, S Taylor, Santon (64' Dummett), Anita (74' Marveaux), Tiote, Sissoko, Ben Arfa, Sammy Ameobi (45' de Jong), Shola Ameobi.
Subs: Yanga-Mbiwa, Haidara, Elliot, Armstrong
NORWICH 0 NEWCASTLE 0
Krul, Debuchy, Williamson, S Taylor, Santon, Anita, Tiote, Ben Arfa (75' Shola Ameobi), Sissoko, Sammy Ameobi (87' Haidara), Remy
Subs: Yanga-Mbiwa, Gosling, Elliot, Dummett, Armstrong
WEST HAM 1 NEWCASTLE 3 (Cabaye 2, Remy)
Krul, Yanga-Mbiwa, Williamson, S Taylor, Santon (74' Dummett), Tiote, Anita (60' Shola Ameobi), Sissoko, Cabaye, Gouffran, Remy (78' Ben Arfa)
Subs: Cisse, Haidara, Elliot, Obertan
NEWCASTLE 0 MAN CITY 2
Krul, Yanga-Mbiwa (82' Ben Arfa), Williamson, S Taylor, Santon, Anita (73' Cisse), Tiote, Sissoko, Cabaye, Gouffran (82' Haidara), Remy
Subs: Gosling, Elliot, Marveaux, Sammy Ameobi
WEST BROM 1 NEWCASTLE 0
Krul, Debuchy, Williamson, Coloccini (65' Yanga-Mbiwa), Santon, Cabaye, Tiote, Gouffran (45' Ben Arfa), Sissoko, Remy, Shola Ameobi (76' Haidara).
Subs: Anita, Cisse, Elliot, S Taylor
NEWCASTLE 0 ARSENAL 1
Krul, Debuchy, Williamson, Coloccini, Santon, Anita (74' Shola Ameobi), Tiote, Sissoko (79' Haidara), Cabaye, Gouffran (62' Ben Arfa), Remy
Subs: Cisse, Yanga-Mbiwa, Elliot, Sammy Ameobi
NEWCASTLE 5 STOKE CITY 1 (Remy 2, Gouffran, Cabaye, Cisse pen)
Krul, Debuchy, Williamson, Coloccini, Santon (61' Haidara), Anita (45' Shola Ameobi), Sissoko, Ben Arfa, Cabaye, Gouffran (72' Cisse), Remy
Subs: Yanga-Mbiwa, Elliot, Obertan, S Taylor
CRYSTAL PALACE 0 NEWCASTLE 3 (Cabaye, Gabbidon og, Ben Arfa pen)
Krul, Debuchy, Williamson, Coloccini, Santon, Anita, Tiote, Sissoko, Cabaye (79' Ben Arfa), Gouffran, Remy (75' Shola Ameobi).
Subs: Cisse, Yanga-Mbiwa, Haidara, Elliot, Obertan
NEWCASTLE 1 SOUTHAMPTON 1 (Gouffran)
Krul, Debuchy, Williamson, Coloccini, Santon (78' Haidara), Sissoko, Anita, Tiote, Gouffran (73' Ben Arfa), Shola Ameobi (61' Cisse), Remy
Subs: Yanga-Mbiwa, Elliot, Obertan, Sammy Ameobi
MAN UTD 0 NEWCASTLE 1 (Cabaye)
Krul, Debuchy (83' Yanga-Mbiwa), Williamson, Coloccini, Santon, Cabaye (78' Shola Ameobi), Tiote, Anita, Sissoko, Remy, Gouffran (57' Ben Arfa).
Subs: Cisse, Gutierrez, Elliot, Obertan
SWANSEA 3 NEWCASTLE 0
Krul, Debuchy, Williamson (77' Yanga-Mbiwa), Coloccini, Santon (56' Haidara), Sissoko, Tiote, Cabaye, Gouffran, Shola Ameobi (67' Obertan), Remy
Subs: Anita, Elliot, Sammy Ameobi, Dummett
NEWCASTLE 2 WBA 1 (Gouffran, Sissoko)
Krul, Debuchy, Williamson, Coloccini, Santon, Sissoko (90+5' Cisse), Tiote, Cabaye, Gouffran, Shola Ameobi, Remy (84' Anita)
Subs: Ben Arfa, Yanga-Mbiwa, Elliot, Obertan, Sammy Ameobi
NEWCASTLE 2 NORWICH CITY 1 (Remy, Gouffran)
Krul, Yanga-Mbiwa, Williamson, Coloccini, Santon, Sissoko, Tiote, Cabaye (68' Anita), Gouffran (83' Ben Arfa), Shola Ameobi (74' Cisse), Remy.
Subs: Haidara, Elliot, Obertan, Sammy Ameobi
TOTTENHAM 0 NEWCASTLE UTD 1 (Remy)
Krul, Debuchy, Williamson, Yanga-Mbiwa, Santon, Sissoko, Cabaye, Tiote, Gouffran (85' Obertan), Remy (75' Cisse), Shola Ameobi (60' Anita).
Subs: Coloccini, Ben Arfa, Elliot, Sammy Ameobi
NEWCASTLE UTD 2 CHELSEA 0 (Gouffran, Remy)
Krul, Debuchy, Williamson, Yanga-Mbiwa, Santon, Sissoko, Cabaye, Tiote (53' Anita), Gouffran (85' Obertan), Shola Ameobi (62' Cisse).
Subs: Ben Arfa, Elliot, Sammy Ameobi, Tavernier.
SUNDERLAND 2 NEWCASTLE 1 (Debuchy)
Krul, Debuchy, Williamson, Dummett, Santon, Sissoko (45' Cisse), Tiote, Cabaye, Gouffran (86' Sammy Ameobi), Ben Arfa, Remy (70' Shola Ameobi).
Subs: Anita, Haidara, Elliot, Obertan.
NEWCASTLE UTD 2 LIVERPOOL 2 (Cabaye, Dummett)
Krul, Debuchy, Williamson, Yanga-Mbiwa, Santon, Cabaye (78' Sammy Ameobi), Tiote, Gouffran, Sissoko (45' Dummett), Remy, Ben Arfa (78' Anita).
Subs: Cisse, Elliot, Obertan, Dummett.
CARDIFF CITY 1 NEWCASTLE 2 (Remy 2)
Krul, Debuchy, Williamson, Coloccini, Santon, Tiote, Cabaye (86' Ben Arfa), Gouffran, Sissoko, Remy (71' Gutierrez), Cisse
Subs: Anita, Yanga-Mbiwa, Elliot, Sammy Ameobi, Dummett
EVERTON 3 NEWCASTLE 2 (Cabaye, Remy)
Krul, Debuchy, Yanga-Mbiwa (46' Williamson), Coloccini, Santon, Tiote, Anita (69' Cisse), Ben Arfa (46' Cabaye), Sissoko, Gouffran, Remy
Subs: Elliot, Obertan, Sammy Ameobi, Dummett
NEWCASTLE 2 HULL CITY 3 (Remy 2)
Krul, Debuchy (86' Tiote), Yanga-Mbiwa, Coloccini, Santon, Cabaye (62' Gouffran), Anita, Sissoko, Ben Arfa, Cisse (73' Marveaux), Remy
Subs: Williamson, Elliot, Sammy Ameobi, Dummett
ASTON VILLA 1 NEWCASTLE 2 (Ben Arfra, Gouffran)
Krul, Debuchy, Coloccini, Yanga-Mbiwa, Santon, Anita (74' Tiote), Cabaye (88' Sammy Ameobi), Ben Arfa, Sissoko, Remy (63' Gouffran), Cisse
Subs: Elliot, Marveaux, S Taylor, Dummett
NEWCASTLE 1 FULHAM 0 (Ben Arfa)
Krul, Debuchy, Yanga-Mbiwa, Coloccini, Santon, Ben Arfa, Sissoko, Anita 65' (Cabaye), Marveaux 74' (Remy), Shola Ameobi 65' (Gouffran), Cisse
Subs: Gosling, Elliot, Sammy Ameobi, Dummett
NEWCASTLE 0 WEST HAM 0
Krul, Debuchy, Yanga-Mbiwa, Coloccini, Santon, Ben Arfa, Sissoko, Anita, Marveaux 66' (Sammy Ameobi), Shola Ameobi, Cisse 72'
Subs: Gosling, Bigirimana, Elliot, Vuckic, Dummett
MAN CITY 4 NEWCASTLE 0
Krul, Debuchy, Coloccini, S Taylor, Yanga-Mbiwa, Sissoko, Tiote, Gouffran 45+4' (Dummett), Ben Arfa 65' (Sammy Ameobi), Gutierrez 44' (Anita), Cisse
Subs: Elliot, Marveaux, Shola Ameobi, Obertan
LEAGUE CUP
NEWCASTLE 0 MAN CITY 2 (AET)
Krul, Debuchy, Williamson, Yanga-Mbiwa, Haidara (45 Dummett, 80 Ben Arfa), Anita, Tiote, Gouffran, Sissoko, Shola Ameobi (66 Cabaye), Cisse
Subs: Remy, Elliot, Obertan, Sammy Ameobi
NEWCASTLE 2 LEEDS UTD 0 (Cisse, Gouffran)
Krul, Debuchy, Williamson, Coloccini, Dummett, Gouffran (90' Vuckic), Anita (80' Gosling), Tiote, Marveaux, Sammy Ameobi, Cisse (71' Obertan).
Subs: Ben Arfa, Yanga-Mbiwa, Bigirimana, Alnwick
MORECAMBE 0 NEWCASTLE 2 (Shola Ameobi, Sammy Ameobi)
Elliot, Debuchy, Yanga-Mbiwa, Good, Dummett, Bigirimana, Gosling, Marveaux 88' (Sissoko), Vuckic 46' (Shola Ameobi), Sammy Ameobi, Gouffran 71' (Ben Arfa)
Subs: Santon, Anita, Alnwick, Streete
FA CUP
NEWCASTLE 1 CARDIFF CITY 2 (Cisse)
Elliot, Santon, S Taylor, Yanga-Mbiwa, Haidara, Sissoko (85' Shola Ameobi), Tiote, Anita, Gouffran (63' Obertan), Ben Arfa, Cisse (85' Remy).
Subs: Williamson, Sammy Ameobi, Dummett, Alnwick