After a rollicking 2019/20 edition of the La Liga drew to a close last week, let us look back at some key moments from the recently concluded Spanish top-flight season.We've already seen how the best players from the La Liga season would line-up in a combined XI. We also had a look at the best XI featuring only Spanish players, while also shedding light on the bright up-and-coming talents in the La Liga.Let's now have a look at the other end of the spectrum - the ones who promised much but delivered little. These are the players who came into the La Liga campaign with tremendous anticipation from their respective clubs and fans alike but flattered to deceive.Without, further ado, let us meet the five players who disappointed the most during the 2019-20 La Liga season.Five players who disappointed the most during the 2019-20 La Liga season:#5: Jasper Cillessen (Valencia)Jasper Cillessen is a quality player, but his hand just doesn't fit the glove at times.Deprived of first-team opportunities at Barcelona, Jasper Cillessen joined Valencia last season for €35 million, making him the most expensive guardameta in the club's history. The switch brought the regular game-time he was looking for, but Cillessen didn't impress enough during the 2019-20 La Liga campaign.His passes were of poor quality and he registered only five La Liga clean sheets. Cillessen was also erroneous at times - most notably on his return to the Camp Nou in September when a horrendous clearance allowed Gerard Pique to strike.Perhaps, the enduring image of his La Liga season is the guard of honour he received on the opening day for the Copa Del Rey final which he lost with Barcelona.If rumours are to be believed, the Bats are now trying to offload him, with a return to Ajax very much on the cards.#4: Joao Felix (Atletico Madrid)Joao Felix was a pale shadow of his former, rip-roaring self at Benfica.The Rojiblancos were the envy of world football last year after capturing Joao Felix from right under the noses of mightier European sides.Costing Atletico Madrid an eye-watering £113 million, Felix was supposed to be the replacement for Barcelona-bound Antoine Griezmann. But it didn't take long for the move to go pear-shaped as the Portuguese star failed to light up the Wanda Metropolitano.He struggled to adapt to Diego Simeone's philosophy, with ankle and leg injuries further taking a toll on his performances.Felix's eventual tally of six goals from 27 La Liga games isn't too shabby for a 20-year-old who is still acclimatising to new surroundings. But when you're the reigning 'Golden Boy' winner and also the fifth-most expensive player in history, the expectations riding on your shoulders are high, perhaps a bit too high at times.