Real Madrid are expected to carry out some serious transfer business in the next few weeks. That includes an exodus of first-team players after reports have emerged that the club's wage cap needs to be slashed by almost £150 million, in accordance with La Liga rules, before the start of the next season.Real Madrid will look to trim their squadReal Madrid's upcoming pre-season fixtures will be key in deciding the future of some of the first-team players as new manager Carlo Ancelotti looks to trim his squad.The likes of Gareth Bale, Martin Odegaard and Luka Jovic have returned from their respective loan deals. Ancelotti is expected to provide a chance to all these players before deciding on their futures.On that note, let's take a look at five Real Madrid players who need to impress in pre-season. Gareth Bale has been excluded from this list, as he has already worked with Ancelotti and might still have the opportunity to help out the first team better than some of the others on this list.So without further ado, let's get started.#5 Daniel CeballosDaniel Ceballos returned to Real Madrid after a two-year loan spell at Arsenal.Real Madrid signed Dani Ceballos from Real Betis in 2017, just weeks before the start of the new season.He was a really skilful player and had performed brilliantly for Real Betis and Spain's under-21 team. But his first two seasons at Real Madrid didn't go according to plan. He started 38 of his 56 La Liga games he played, scoring just five goals.In search of more playing time, Ceballos went on loan to Arsenal for the next two seasons. He started the first season brilliantly, but then simmered down a bit. Since then, Ceballos has only shown flashes of his brilliance but has not performed consistently.His second season did not go too well, though. So, as expected, Arsenal chose not to sign the Spaniard on a permanent deal.🔴⚪️🙌🏻Thanks @Arsenal and thanks to all Gunners.🙌🏻💪⚽️I wish you all the best and the success that I'm sure will come. ⚽️💪🙌🏻Let's go Gunners!🙌🏻Goodbye👋🏼🤗THANKS FOR ALL! pic.twitter.com/61M6MsucRp— Daniel Ceballos (@DaniCeballos46) May 25, 2021Now, under new manager Carlo Ancelotti, Dani Ceballos is back at Real Madrid. He will be determined to prove himself and fight for a place in the starting XI. He said after returning from Arsenal:I really want to win at Real Madrid. I’ll fight to stay here. It’s clear. I would like to play at Real Madrid. But I have to know what the coach wants, and there have to be objectives. But my intention is to play the coming year at Real Madrid.Amid the presence of three senior figures in Casemiro, Luka Modric and Toni Kroos and the return of Martin Odegaard, also from Arsenal, Ceballos will have an uphill battle to impress Ancelotti. He will not be helped by the fact that he will return late following his Olympic call-up for Spain.#4 Mariano DiazMariano Diaz struggled for game time under Zinedine Zidane.Real Madrid academy graduate Mariano Diaz has not lived up to expectations since his return to the club in 2018.The 27-year-old forward returned to the club after a year-long spell with Lyon, during which he scored 21 goals in 48 games. But since his return, Diaz has found game time difficult to come by and has failed to make the most of whatever few opportunities he has had during the past three seasons.With Luka Jovic back from his loan spell and Carlo Ancelotti looking to sign a new striker to provide cover for Karim Benzema, Mariano is living on borrowed time at Real Madrid.Today, Real Madrid played a friendly game against Fuenlabrada at Valdebebas. According to COPE, Real Madrid won 3-1. Mario Gila, Mariano Diaz & Martin Ødegaard were the goalscorers. pic.twitter.com/9CcovUfeUp— Real Madrid News (@onlyrmcfnews) July 11, 2021Many of Real Madrid's first team players are still on holiday because of their international commitments. Hence, Diaz will have plenty of opportunities in the pre-season to impress Ancelotti and prove that he could play a key role for the first team next season.