The summer transfer window is slowly shifting gears. Having begun with low-cost and free transfers, the big guns across Europe are slowly getting back into the groove.While these clubs will be looking to improve on their prospects for the upcoming season, there are also plenty of players who desperately need a change of scenery. These individuals have simply fallen down the pecking order at their respective clubs. The summer window allows them the opportunity to redirect their careers and play important roles for their team regardless of where they end up.On that note, let's look at five players who sorely need a transfer to go through if they are to revitalize their careers:#5 Saul Niguez | Atletico Madrid Saul NiguezMany will know Saul Niguez as an Atletico Madrid stalwart; so much so that it's easy to forget he is only 26.The Spaniard joined Diego Simeone's side back in 2013. He played a crucial role as Atletico won the 2013-14 La Liga title and made an incredible run to the UEFA Champions League final. Fast forward seven years and he started just 22 league games as the Colchoneros won the league in the 2020-21 season.While Saul hasn't always been the rugged, 'Simeone player,' he often breathed fresh air into a rigidly organized Atletico side. The midfielder has played 337 matches in his time with the club, scoring a handy 43 goals. However, Simeone's decision to switch to a back three during the 2020-21 campaign massively affected Saul's playing time.In previous seasons, Saul played as one of the midfielders in a 4-4-2 system that held the fort in the defensive half and survived on quick transitions offensively. However, the 3-1-4-2 system that Simeone has adopted now means Koke plays as the holding midfielder with space for only two other midfielders in the four ahead. El Cholo often selected the prolific Marcos Llorente alongside an inside forward in Thomas Lemar, which effectively left no space for Saul in the XI.After another day of negotiations, there’s still no final agreement between Barcelona and Atletico Madrid for Griezmann-Saúl swap deal. Talks ongoing but no agreement yet. 🔴 #FCB #AtletiSaúl also has received bids from Premier League clubs and Atléti are prepared to sell him.— Fabrizio Romano (@FabrizioRomano) July 16, 2021Saul has played a crucial role in whatever success Atletico have had in recent years. However, it might be in the best interest of both parties if the Spaniard leaves the club this summer, with a move to Barcelona reportedly on the horizon.#4 Gabriel Jesus | Manchester CityGabriel JesusGabriel Jesus is still one of the hottest prospects in Brazilian football at just 24 and has won trophies aplenty with Manchester City. However, his future at the club has been a consistent question mark over the last couple of seasons.With Sergio Aguero departing for Barcelona, it is easy to assume Jesus might play a more starring role in the 2021-22 season for the Cityzens. However, it's worth noting that Aguero spent much of the last campaign out due to injury. Despite that, Jesus made just 22 Premier League starts during City's title-winning run.There is little doubt about the Brazilian's talent. He has 82 goals and 34 assists for City in 195 matches, many of which he hasn't started in. But Jesus is often profligate in front of goal and takes time in every game to find his range.This is a quality Pep Guardiola doesn't really seem to care for. The City manager's decision to play one of Phil Foden, Riyad Mahrez, Raheem Sterling and Kevin de Bruyne as a false nine ahead of Jesus in crunch games only emphasizes that even more.Juventus have reportedly asked Manchester City for Gabriel Jesus, on loan (with a high loan fee) as well option to buy at the end of the season.[Football-Italia]#mancity #mcfc #gabrieljesus #juventus pic.twitter.com/PZYvSejnDV— MCFC_LADS (@MCFC_LADS) July 16, 2021There is just so much unpredictability in the City set-up, thanks in no small part to Guardiola's plethora of tactical nuances. Rumors have also been repeatedly floating around that the Sky Blues want Harry Kane this summer. In such a scenario, one just feels Jesus might benefit by transferring to a side that uses him as a conventional number and gives him the playing time he deserves.