Ben Shelton faced an unexpected defeat against World No. 289 Paul Jubb in the quarterfinals of the Mallorca Championships. Shelton's exit from the ATP 250 event left several fans baffled, with many raising concerns regarding his poor form during the grass campaign.Shelton has struggled since his grasscourt campaign began at the BOSS Open, exiting in the second round against James Duckworth. He then lost in the first round to Giovanni Mpetshi Perricard at the Queen's Club Championships. Despite a promising start at the Mallorca Championships with a straight-sets win against Rinky Hijikata, Shelton succumbed to an unexpected quarterfinal defeat to Paul Jubb.Jubb started well, defeating the American 6-3 in the first set. However, Shelton bounced back strongly, winning the second set 6-3 and taking the match to a decider. In an intense third set tie-breaker, Shelton had a match point on serve at 8-7, but the 24-year-old Brit rallied, winning three straight points to upset the World No. 14.Jose Morgado, a tennis journalist, highlighted the news of Ben Shelton's shocking loss."Wow. Paul Jubb, who had zero ATP level wins before this week, beats top 15 Ben Shelton 6-3, 3-6, 7-6(8) to reach the semifinals in Mallorca. Incredible 3rd set. Saved 1 match point and needed 7."Tennis fans took to the comments section to react to Ben Shelton's defeat, with one fan seemingly hinting towards Ben Shelton's feud with Novak Djokovic:"Ben Shelton fell off so badly. Teach your kids respect. Things can change anytime," the fan wrote."Shelton all the serve bot power and shit and like wtf is this , so fuc*ing embarrassing lawd like are you washed already???" a fan wrote."This bum JUBB will not be seen again until another grass season. That shows you how poor SHELTON as a player is. And a reminder to those who think having a strong serve is just enough to be good on grass," another commented.Here are more reactions from fans expressing their disappointment at Ben Shelton's surprise quarterfinal exit."This Shelton boy is very unserious," one fan wrote."Imagine this happening to any top WTA player.." another pondered."Wow Shelton!! terrible miss on match point!!" another one commented.Paul Jubb, a former NCAA champion, has had a great campaign so far in Mallorca, defeating the likes of Maximilian Marterer and Adam Walton in straight sets before upsetting Shelton to advance to his maiden ATP semifinal.Ben Shelton may face a challenging 2024 Wimbledon Championships campaignBen Shelton at 2023 US Open - Day 12After his exit from the ATP 250 event in Mallorca, Ben Shelton will next play at the Wimbledon Championships. Although Shelton is the favorite to win the opener against World No. 150 Mattia Bellucci, he might have a challenging campaign ahead.Based on the draw, the American is expected to reach at least the third round at SW19, where he might face Nicolas Jarry, Daniel Altmaier, or Denis Shapovalov.If he reaches the fourth round, Shelton could face No. 1 seed Jannik Sinner, who comes into Wimbledon after winning the Terra Wortmann Open in Halle. The Italian also made it to the semifinals of the 2024 French Open, and his current momentum could present a significant challenge for Shelton.2024 will mark Shelton's second appearance at Wimbledon, following his early second-round exit in the Grass Major last year.