With Manchester United's 2-0 win over Ajax in Wednesday's Europa League final, the English Premier League will have five teams competing in next season's UEFA Champions League.

After not taking part in Europe's premier club competition this season, Chelsea, United and Liverpool are all returning to the Champions League. Manchester City and Tottenham, meanwhile, will try to improve on this season's early exits. City went out to Monaco in the Round of 16, and Spurs failed to progress past the group stage.

It's been a tough go of it in recent years for English clubs in the Champions League. This year marks the fifth straight season without a Premier League side in the final, and an English club has lifted the Champions League trophy just once since United's win in 2007-08, with that one time being Chelsea's underdog -- and still incomprehensible -- run to glory in 2012.

While the English sides appear to be a ways off from challenging the current European powers -- Real Madrid, Barcelona, Bayern Munich, Juventus and Atletico Madrid -- each of the five teams can move to close the gap with a productive summer on the transfer market.

With that in mind, let's take a look at the biggest area of need for each of England's five Champions League qualifiers.

Chelsea

If there's one Premier League side who may be able to hold their own against Europe's current guard, it's Chelsea. Antonio Conte's men performed superbly this season on their way to a rather straightforward Premier League title, and the side already includes world-class talent such as N'Golo Kante, Diego Costa, Eden Hazard and Thibaut Courtois.

Kante won the PFA Player of the Year Award, and he made a massive impact in his first year in London, further enhancing his reputation as a ball-winning machine in midfield.

The top-end of the Blues' roster looks pretty nice, assuming they retain their stars. What Chelsea needs is a boost in squad depth.

Conte's team benefited greatly this season from not having to play in the Champions League. Prior to making drastic lineup changes after clinching the Premier League title, Chelsea only made 38 total changes to their starting XI through their first 36 league matches. Not only was that the fewest changes in the league this season, typical title-contending sides make upwards of 100 lineup changes due to having to compete both domestically and in Europe (and in England's two league cups).

The addition of Champions League fixtures next season will put a new strain on Chelsea, testing their squad depth like it wasn't tested this year. The Blues' starting XI is in great shape, but they need to bring in some reinforcements this summer, players who can either challenge for a starting role or serve as a quality backup for squad rotation

Tottenham

Spurs were outstanding this year, putting together their best-ever finish in the Premier League as they placed second behind Chelsea. It was Tottenham's second straight best-ever league showing under star manager Mauricio Pochettino after Spurs finished third in 2015-16.

Tottenham's biggest offseason battle may be retaining their stellar young core. Just about all of their top-notch youngsters -- Eric Dier, Dele Alli, Christian Eriksen, Danny Rose, Kyle Walker and Harry Kane (OK, you get it) -- have been linked with a move away from north London.

If they can preserve their core -- and make sure Pochettino sticks around -- Tottenham could develop into a top-four mainstay in the Premier League. The biggest need, similar to Chelsea, will be a lift in bench talent as there aren't many soft spots in Spurs starting XI.

However, if Spurs lose any of their key cogs to bigger clubs, replacing them will become their most vital need.

Manchester City

Pep Guardiola's first season was something of a disappointment. Guardiola was brought in to make City a European power, but he was unable to conquer England as the club finished a distant third.

City's attack is plenty strong as they netted 80 goals in 38 Premier League matches, the third-most in the league. The Citizens' weakness is at the back. The year-end numbers don't look too bad -- 39 goals in 38 league fixtures -- but the defense was exposed against top competition.

Never were City's strengths and weaknesses more apparent than across the two legs of their Champions League Round of 16 tie against Monaco. City scored six times in the tie, but they also allowed three goals in each leg as Monaco opened them up all too easily and advanced via away goals.

Guardiola bought center-back John Stones for a reported £47.5 million last summer, and it's probably safe to expect the former Barca and Bayern manager to splash more cash to upgrade his defense.

With attack-minded players such as Gabriel Jesus, David Silva, Leroy Sane and Kevin de Bruyne, an improved defense could get City over the hump and back atop the Premier League.

Liverpool

The Reds clinched their spot in the top four -- thereby securing a berth in the Champions League qualifying rounds -- with a 3-0 win over Middlesbrough on the final day of the Premier League season. But they have a lot of work to do to fine tune the squad for next year.

Liverpool are actually in a very similar situation as Manchester City -- the Reds are special in attack while lacking defensively. Philippe Coutinho, Sadio Mane, Roberto Firmino and Adam Lallana provide manager Jurgen Klopp with plenty of firepower going forward as Liverpool scored 78 goals in league play.

The issue is the Reds also conceded 42 goals -- significantly more than the top-notch defenses of Chelsea (33), Spurs (26) or Manchester United (29).

Klopp has already proven to be a savvy investor in the English transfer market, striking a deal last summer to land Mane, who proved to be an influential player for the Reds when he was healthy. This summer, though, Liverpool will need to invest at the other end of the pitch. Center-back is likely the most pressing need, but a defensive midfielder who does work in the engine room would be a big lift, too.

While Liverpool are set in attack, that could change if the Coutinho-to-Barca rumors come to fruition. If the Brazilian is lured away to the Camp Nou, the Reds would be in the market for a playmaking midfielder. Also, Klopp's frenetic pressing tactics will make the additional Champions League matches even more of a burden, so some depth signings would be beneficial, as well.

Manchester United

United is back in the Champions League despite a disappointing sixth-place finish in the Premier League. They punched their Champions League ticket by winning the Europa League, but, as you might imagine for a sixth-place squad, there's a lot of work to be done this summer.

Fortunately for the Red Devils, they have the money to make just about any upgrade they want, and they aren't afraid to make a splash, as demonstrated by last summer's world record signing of Paul Pogba.

The most pressing need is in attack. United -- a club known for attacking flair and creativity -- was rather stale this season as the Red Devils scored a meager 54 goals. That's 32 less than league-winners Chelsea tallied, and it's also 1 fewer than Bournemouth scored. Simply put: it's not good enough for Manchester United.

The lack of goals wasn't Zlatan Ibrahimovic's fault. Another big signing from last summer, Ibra was immense this year, scoring 17 times in 27 appearances, but he will miss a chunk of next season with a torn ACL (and his contract expires this summer).

Youngster Marcus Rashford looks to be a promising young piece around which Mourinho can build his attack, but with Anthony Martial falling out of favor and being relegated to bench duty, United need to add pace and playmakers up front.

The Red Devils have long been rumored to be after Atletico Madrid striker Antoine Griezmann, who would provide an immediate lift to their goal-scoring punch. It remains to be seen if that move will happen, but expect United to chase some attacking talent in the upcoming transfer window, namely a big-time striker.

United's needs don't stop there. The squad could also use a defensive-minded midfielder to free up Pogba to do more in attack (although he wasn't as bad this season as the narrative would have you believe), and goalie will be a massive need if they lose star man David de Gea, who has been linked to Real Madrid.