Another Idiomatic Expression from Lorenzo NA1

I received an email message from a student, Lorenzo, who offered another idiomatic expression for our class vocabulary. Here is the message:
 

" Hello David, I was reading about Formula 1 and I found this idiomatic expression:
   
  "... The German is reported to be heading to Ferrari where he will take Alonso's seat. Speculation, meanwhile, has Alonso returning to McLaren with whom he spent a troubled year in 2007.The double World Champion, however, is keeping his cards close to his chest.  ..."

The Spanish translation could be "... no muestra sus cartas." As you can see it's a very similar expression."

Thanks to Lorenzo for this offering. In fact, there are a lot of card-related expressions in English and in Spanish, too.