WATCH LaLiga LIVE on beIN SPORTS | Sign up to take advantage of our 7-day FREE TRIAL here | AU | NZ

Vinicius, who scored 22 goals last season, has managed just five across all competitions this term and is goalless in his past 15 matches.

The 25-year-old was booed by sections of fans during Madrid's 2-0 home win over Sevilla on 21 December (AEDT), and was taken off alongside Rodrygo, who provided two assists against Betis, in the 77th minute to a mixed reaction on Monday (AEDT).

But Alonso downplayed the situation.

"Vini has contributed a lot, he came on very well, he was persistent and disruptive. I liked his performance, with everything he gave us. He's going to be crucial in the Super Cup," Alonso said.

"We understand the situation. Vinicius is mature, and so are we. We must respond. We are all here to support each other. We want to give our best.

"Vini is and has been fundamental at Madrid, and he will continue to be so. I'm sure the Bernabeu will applaud him in the future, I have no doubt about that."

Gonzalo Garcia seized his chance by scoring a hat-trick in the absence of the injured Kylian Mbappe to help Madrid emphatically beat Betis, with Alonso praising the 21-year-old forward's attitude and performance.

Garcia, who lit up last year's FIFA Club World Cup with four goals, was named in the starting line-up after LaLiga's top scorer Mbappe was sidelined by a knee injury.

Unfazed by the pressure, Garcia helped to trim Madrid's deficit to current league leader Barcelona to four points. Alonso's side, which led the league before a downturn in November, now has 45 points from 19 matches, second behind defending champion Barcelona.

"Gonzalo obviously had a dream match for him at the Bernabeu in his first season, scoring a hat-trick," Alonso said.

"He was eager to score ... I'm very happy for him, for the daily work he does, when he plays and when he doesn't, he has an impressive attitude. He's a great example of what a Madrid youth player is. I congratulate him very much, he deserved the opportunity. I encourage him to keep it up.

"Today, football requires you to work as a team, with and without the ball. The forwards start the pressure. Gonzalo understands that very well. And if you add his defensive quality to his goals, that's a great thing."

Asked if Mbappe, Vinicius Jr., Rodrygo and Garcia could all fit together, Alonso replied: "Why not? It's my decision. There are many matches, we'll have to see how things go and what's needed. Nothing should be ruled out."

Madrid face city rival Atletico Madrid in the Spanish Super Cup semi-finals on Friday, Atelti unable to impress in its match on Monday (AEDT) at Real Sociedad, where it let a lead slip to draw 1-1.