Ruben Loftus-Cheek is facing a period of rehabilitation that will stretch well into next season after rupturing an achilles during Chelsea’s Final Whistle on Hate charity match against New England Revolution.

The England midfielder, who had surgery on Thursday, fell awkwardly barely 20 minutes after his introduction as a half-time substitute at Gillette Stadium, near Boston. He had to be helped back to the dressing room by two of the medical staff and departed on crutches wearing a protective boot on his left foot.

Loftus-Cheek, who will miss the Europa League final and next month’s Nations League finals in Portugal, is the second Chelsea player to have an achilles injury in the season’s run-in, with his international teammate Callum Hudson-Odoi having had surgery after fully rupturing the tendon during last month’s draw with Burnley. “Callum and Ruben would definitely have been in this squad,” said Gareth Southgate, as the England manager named his initial party for the finals.

Chelsea are confident N’Golo Kanté will have recovered from a hamstring complaint to feature against Arsenal in the Europa League final in Baku but Loftus-Cheek’s absence constitutes a considerable blow.

The midfielder has enjoyed the best form of his Chelsea career since overcoming the latest bout of back trouble this year, and has been a driving force through the midfield over recent weeks and contributed 10 goals in all competitions. Four of those came in the Europa League, in which he has been a regular. The incident confirmed Maurizio Sarri’s worst fears about the timing of the charity match, which raised around £3.1m to combat discrimination with around 27,000 in attendance. Chelsea play in Baku on 29 May and the manager had hoped his players might benefit from a more prolonged rest rather than flying immediately to the US on the conclusion of the Premier League campaign.

Ruben Loftus-Cheek suffers the injury after coming on at half-time. Photograph: Darren Walsh/Chelsea FC via Getty Images

The game against Arsenal is likely to be Gonzalo Higuaín’s final appearance in a Chelsea shirt, with the club having decided not to trigger an option to extend his loan or make his move from Juventus permanent. The Argentinian, whose signing was championed by Sarri, has five goals in 21 appearances since joining in January on an initial six-month deal. It would have cost Chelsea €18m (£15.7m) to extend that to 2020, or €36m to sign him outright, but the 31-year-old is expected to return to Turin.

Olivier Giroud, the Europa League’s joint leading scorer, is likely to stay, with the club to trigger a one-year option on his contract, while attempts will be made to secure Mateo Kovacic from Real Madrid on a permanent deal, depending on the club’s ability to have their two-window Fifa transfer ban frozen by the court of arbitration for sport.