With Manchester United's Premier League campaign set to begin on August 7 against Brighton and Hove Albion, the lack of depth in the forward department is worrying. Cristiano Ronaldo wants to leave the club this summer, a stance that was re-emphasized in a meeting earlier this week as the Portuguese returned to training.Anthony Martial enjoyed a terrific pre-season and is set to lead the line for United at Old Trafford against Brighton. Wingers Marcus Rashford and Jadon Sancho have also looked extremely sharp in pre-season, which is a positive sign for United.However, when you look at the depth in this department, the drop-off in quality is huge. New manager Erik ten Hag lacks options in the front three, making an injury to either of the three forwards detrimental. The club is thus actively looking for attacking options this summer to provide depth to their lineup. On that note, we will look at three players they could sign this summer to bolster their attacking options. #3 Memphis DepayFC Barcelona v Inter Miami CF - Pre-Season friendlyA return to Old Trafford for Memphis Depay is gathering some weight, according to Spanish journalist Gerard Romero. It is understood Manchester United are interested in the Dutch forward and given Barcelona's financial situation, there is a possibility this deal could get done.Since leaving United, Depay has improved massively and is one of the best strikers available in the market currently. The forward was the highest goal-scorer for Barcelona last season, netting 13 goals in 37 appearances across all competitions. Many feel Depay was not given a fair chance at United as Jose Mourinho barely used the forward which led to his departure. The Dutchman posesesses the abilities required to play in Ten Hag's system due to his positional fluidity as he can also operate on the left.Transfer News@TransfersLlVEMan Utd have offered €20m to Barcelona to sign Memphis Depay.69745Man Utd have offered €20m to Barcelona to sign Memphis Depay. https://t.co/XDOsraTjUjThere is, of course, an element of risk as Depay has played in England before and failed to heavily impress. However, it must not be forgotten that he is a much more polished player now, and would add quality and depth to United's attacking department.#2 AntonyAFC Ajax v Borussia Dortmund: Group C - UEFA Champions LeagueManchester United have been linked with Brazilian winger Antony all summer due to his time with Ten Hag at Ajax. The Brazilian was one of Ajax's best performers last season, with 12 goals and 10 assists in 32 games across all competitions. One issue with this deal is the transfer fee Ajax are looking to recoup for the player. As reports suggest, the Dutch club are looking for a fee in the region of £84 million for their winger.This could complicate matters for Manchester United, who are still looking to sign Frenkie de Jong, which will require a large chunk of their transfer budget this summer. That said, Antony would add an element of quality and depth to United's attacking department. Antony Santos@antony00I’m back! 331911790I’m back! ✅⚽️ https://t.co/c3aU2tyFIzAccording to transfer expert Fabrizio Romano, the Brazil international wants to move to Manchester United. Personal terms, thus, aren't expected to be a problem. #1 Benjamin SeskoBrondby IF v FC Red Bull Salzburg - UEFA Champions League: Play-Offs Leg TwoManchester United are tracking 19-year-old striker Benjamin Sesko from Red Bull Salzburg. The Slovakian forward broke into the first team at Salzburg last season with 5 goals and an assist in 24 appearances in the Bundesliga. Sesko may not possess the profile to lead United's attacking line this season, but he is definitely a talented player.Manchester United need options in the forward department and Sesko would be an astute signing. Ten Hag has a tremendous reputation for developing young players and given the fact that Sesko is just 19-years-old, he is a player for the future. The Slovakian recently scored in a pre-season fixture against Liverpool, which has already gone down well with the Old Trafford faithful.FC Red Bull Salzburg EN@FCRBS_enA look at Benji Sesko's goal from close range!68149A look at Benj🔝i Sesko's goal from close range! https://t.co/NHux1C8WZ4Salzburg has a great history of producing talented players and Sesko has been compared to the likes of Erling Haaland.