Arsenal have been left sweating over the condition of Bukayo Saka after the winger was forced off with an injury during Thursday's pre-season defeat to Tottenham Hotspur. The 23-year-old was left worse for wear after an innocuous challenge from Spurs forward Mathys Tel, going to the ground seemingly holding his thigh.

Saka received treatment during a cooling break shortly afterwards, before Mikel Arteta hauled him off as part of a raft of substitutions. Arsenal's injury concerns worsened less than 10 minutes later when Leandro Trossard, who was among the seven players brought on, had to make way for Reiss Nelson with an issue.

The Gunners suffered a 1-0 defeat to their rivals at the Kai Tak Stadium in what was the first north London derby to take place outside of the UK.

Spurs boss Thomas Frank earned a scalp in his derby debut, courtesy of Pape Matar Sarr's audacious lob from just inside the Arsenal half on the brink of half-time.

David Raya was far out of his goal as he played a short pass to Myles Lewis-Skelly, but the 18-year-old lost possession as he moved in-field.

Sarr produced the tackle, progressed with the ball, took one look up and scooped a pinpoint effort over the backtracking Raya from over 40 yards away.

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Arsenal were not at the races beyond the opening 10 minutes, but excited fans by handing new striker Viktor Gyokeres his debut in the final 15 minutes.

Arteta's side had beaten AC Milan 1-0 and Newcastle United 3-2 earlier in pre-season as they prepare to launch another Premier League title challenge.

Arsenal will round off their schedule with a meeting against Villarreal before facing Athletic Club in the Emirates Cup.

The Gunners start the Premier League season with a blockbuster trip to Manchester United as part of a tough opening set of fixtures.

Their visit to Old Trafford is followed by matches against Leeds United, Liverpool, Nottingham Forest, Manchester City and Newcastle United.

After full-time in Hong Kong, Arsenal midfielder Declan Rice cut a positive figure as he thanked the fans and looked ahead to the next outing.

He said: "It's been really, really special coming to Hong Kong. Thank you so much [to the fans] for your support. Even though we lost, we love you guys.

"It's been an incredible trip, we've really felt the love, and that's pushed us on. We lost tonight, but we have another game on Wednesday. It's still pre-season, and we're going to push for big things this season."