Barclays is scrambling to make up for the gap left after the suspension of six currency traders last week amid a sprawling probe into possible efforts to manipulate foreign-exchange markets, according to people familiar with the bank.

The suspensions, which were carried out on Friday, were focused on Barclays's trading desks that specialize in currencies of 10 of the world's biggest economies, according to people familiar with the suspensions. That left the so-called G-10 spot desk in London, which normally would only have roughly a half-dozen employees, short-staffed, these people say.