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Arsenal goalkeeper Petr Cech was substituted with a calf problem during his team's clash with West Bromwich Albion on Saturday.
The veteran's withdrawal was confirmed by the Baggies' Twitter feed, and David Ospina replaced the Arsenal man between the sticks:
Broadcasters noted the Czech Republic star suffered a calf issue while knocking a simple square ball to Shkodran Mustafi.
Losing Cech is a big blow for a Gunners team that can be fragile at the heart of its defence.
It's a group that needs a commanding, experienced presence behind them to dictate and calm things in the box.