“Matt Barrows: One of the big plays in the recent playoff game between these teams came when then-nickel cornerback Jimmie Ward deflected a Dak Prescott pass to Fred Warner for an interception. It seems like that nickel spot will be critical Sunday, too. For one, that’s where Dallas’ top receiver, CeeDee Lamb, likes to line up. And it’s where the 49ers are having a bit of an identity crisis. Will Lamb be going against Isaiah Oliver or Deommodore Lenoir? And if it is Lenoir, will that mean Ambry Thomas is on the field? It seems like something the Cowboys can exploit and might result in the final score being higher than it’s been in recent years.