Arsenal's Petr Cech out against Tottenham after suffering injury
Arsenal goalkeeper Petr Cech will miss the crucial North London derby against Tottenham after being injured near the end of the 2-1 loss to Swansea on Wednesday.
Cech seemed to be clutching his hamstring after running up for an Arsenal corner in the final minute of injury time as the team chased an equaliser, and Arsene Wenger said he has a "muscular problem."
"He had a little groin problem before the game, and I think he struggled a bit today," Wenger said. "He will not play on Saturday. ... I do not know for how long he will be out."
That means David Ospina will get a rare league start in one of the most important games of the season, with Arsenal still three points behind Tottenham going into this weekend's clash at White Hart Lane.
Ospina has only played in two FA Cup games since his blunder helped give Olympiakos a 3-2 win in the Champions League in September.
"I trust Ospina completely, I have no problem with that," Wenger said.
With Arsenal and Tottenham both chasing leaders Leicester in the Premier League title race, Saturday's game promises to be the most important North London derby in years.
But Arsenal will also be without Laurent Koscielny for the clash. The centre-back missed Wednesday's game with a calf injury, and Wenger said he will not be fit by the weekend.
"He will not play on Saturday as well," Wenger said.
Mattias is ESPN FC's Arsenal correspondent. Follow him on Twitter: @MattiasKaren.