Manchester City were dealt a fresh injury blow after their 1-0 at Leeds United in addition to losing Erling Haaland, who missed the trip to Elland Road with a minor knee problem. City's top scorer sustained the injury in Thursday's training session although Pep Guardiola insisted it was "not a big issue". City's injury problems deepened during the match as another key player was forced off.Nico O'Reilly had to be substituted in the 70th minute with a suspected ankle injury. The academy graduate, who started in midfield, went down holding his ankle and could be saying the words "not good" to Bernardo Silva. O'Reilly was immediately replaced by Tijjani Reijnders. City were leading courtesy of Antoine Semenyo's goal at the end of the first half and they held firm in the face of a late onslaught from the home side to move two points behind Premier League leaders Arsenal with 10 games remaining.O'Reilly has quietly been one of City's most important players this season. He has filled in at left-back, holding midfield and more recently attacking midfield. His injury is a huge concern for City and not just because of his versatility. He has scored six goals and contributed five assists in all competitions and last week fired City to a priceless win over Newcastle with two strikes."What a player," Guardiola said after the Newcastle win. "He played full-back, holding midfielder, he can now play in his position. He has made an incredible step up. Nico gives us that physicality that we need in the middle. He is so complete and so young."O'Reilly's injury is also a concern for England less than a month before the friendlies against Uruguay and Japan. O'Reilly was set to be included in the squad for the final World Cup warm-up games on home soil having been called up by Thomas Tuchel for the October and November matches. Despite his limited experience, O'Reilly is shaping up to be Tuchel's first-choice left-back for the World Cup due to a lack of options, with Tino Livramento out with a hamstring injury and Myles Lewis-Skelly getting limited opportunities at Arsenal.Add GOAL.com as a preferred source on Google to see more of our reportingCity's narrow victory over Leeds put them two points behind Arsenal with 10 games remaining in the season. The Gunners can increase the gap when they host Chelsea on Sunday but then City will have a game in hand against Crystal Palace. Guardiola's side have the added advantage of being at home in a potential title decider against Arsenal in April. And if they win their remaining games, including the showdown with the Gunners, they will be champions.Match-winner Semenyo stressed how important it was to keep their destiny in their own hands. He told Sky Sports: "It means everything! We just want to win all our games, and whatever Arsenal do we'll just have to wait and see. We just need to control what we can control, win our games, and we'll see what happens."Guardiola said he did not know when Haaland would be available again while he was not asked about O'Reilly's injury.