Both players have starred under Roberto Martinez as Belgium won all three of their Group G games against Panama, Tunisia and England, which has seen them pitted against Group H runners-up Japan.
Fellaini had even more to celebrate on Friday as it was announced he had extending his Manchester United contract until 2020 with the option of a further year, but the news has been fairly ill-received by supporters.
Courtois has backed the 30-year-old midfielder though, and has endorsed him as a ‘useful’ player on the pitch after a solid performance in the 1-0 win against Gareth Southgate’s England on Thursday night, courtesy on a wonder strike from ex-Man United star Adnan Januzaj.
Courtois said: “Well I think Marouane is a player that often is criticised by a lot of fans, but I think he’s a very useful player. You can always kick a long ball to him, he’s strong, he can keep the ball.
“I think [against England] showed he can dribble, he passed some defenders as well. I think he’s a very useful player. I don’t say you will need him every game, I think managers decide, obviously, it depends on what of opponent they face, but I think he’s a very good to have in your team.
“I said when we played, for example, against Manchester [United] this year and we were winning 1-0, he came on, I didn’t like seeing him on the pitch because I knew they would put balls into the box, and he will have a header or he will deflect the ball to another guy.
“You always have to be very careful when he’s on the pitch, so I think he’s a very useful player.”
The 6 ft 4 midfielder has regularly been used as a scapegoat since joining from Everton for £27m in 2013, but players and coaches all have nothing negative to say about his impact in the dressing room and on the pitch.
Belgium are being touted to go far in Russia this summer, but once their campaign is done Fellaini can start think about joining United on the tour of the United States as pre-season preparations commence.