Ruben Amorim has offered a worrying injury update on star striker Benjamin Sesko. Manchester United played out a breathless 2-2 draw with Tottenham on Saturday afternoon as Matthijs de Ligt netted a last-gasp equaliser to stretch their unbeaten run to five games. However, Sesko was forced off in second half injury time after the summer signing suffered a knee injury in the capital.Bryan Mbeumo had headed United in front on the half hour mark after the Manchester giants rode out an early Tottenham storm. Spurs pressed for an equaliser after the break and were duly rewarded late on as Mathys Tel saw his effort deflect past Senne Lammens.Richarlison then thought he'd won the game for Spurs in second half injury time as he inadvertently headed Wilson Odobert's effort past the Belgian shotstopper but there was still time for United to claim a result as De Ligt rose highest to meet a late Bruno Fernandes corner to head past Guglielmo Vicario.Sesko, though, didn't finish the game in north London having suffered a knee injury after Tel's equaliser. The former RB Leipzig man was introduced in the 58th minute as United pushed to kill the game off.The 22-year-old had a golden chance to restore United's lead shortly after Spurs went level as he was slipped through on goal. As Sesko went to pull the trigger, however, Micky van de Ven made a stunning last-ditch challenge to deny the striker from netting what would have been his third league goal of the season.Sesko, though, picked up an injury as a result of the challenge and limped off the Tottenham Hotspur Stadium pitch in the dying moments of the 90. United had already made all five substitutions, meaning they ended the game with 10 men.After the draw, Amorim was asked about Sesko's form, the summer signing having scored just two goals in 11 league appearances following his arrival from RB Leipzig, but the United boss was more concerned about the striker's injury.When questioned about the form, Amorim responded: "That is not the biggest concern now. That happens, especially with a striker. I am more concerned with an injury, because it's in the knee, we don't know, we need Ben to be a better team. I have no idea. Because it's the knee we never know."Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!Amorim was also asked whether United will need to dip into the transfer market in January to potentially sign a new striker after Sesko's injury. The Premier League side will likely lose both Bryan Mbeumo and Amad Diallo to Cameroon and the Ivory Coast, respectively, for the Africa Cup of Nations, which starts in Morocco next month.When quizzed on the January window over Sesko's injury and AFCON, Amorim replied: "We have to check everything, we have to check what’s happened with Ben. Let's see when the window is open if we can improve the team and trying to repair something that happened. Until then we have to take the chance. We'll see."Both Amad and Mbeumo linked up for the first goal as the former picked out the latter in the first half to put United ahead at Tottenham. Mbeumo was named the Premier League Player of the Month for October in the week, and his goal against Spurs means he's now struck four times in his last four league outings.United have been relatively fortunate with injuries this season, with Lisandro Martinez and Kobbie Mainoo the only missing players ahead of Saturday's game at Spurs. The Argentine hasn't played since February owing to an ACL injury but is likely to return to action later this month.Mainoo, meanwhile, missed the game in the capital owing to a minor injury, though he wouldn't have started anyway. The England international has barely featured for United this season and finds himself behind Bruno Fernandes, Casemiro and Manuel Ugarte in the midfield pecking order.A January exit for Mainoo has been mooted with Napoli a potential destination for the 20-year-old. If he were to move to the Serie A champions, then he'd link up with former United stars Scott McTominay, Rasmus Hojlund and Romelu Lukaku.