The fourth weekend of MLS action is here and still features some teams without a blemish on their season, while others look to prove themselves. After three weeks, no teams have looked better than the perfect-record Vancouver Whitecaps FC and Philadelphia Union.

Atlanta is winless in two in its start to the Ronny Deila managerial era, settling for a 0-0 draw against the NY Red Bulls last weekend. But striker Emmanuel Latte Lath appears to be out of the league's concussion protocol in time for the encounter. And of course, the last time these sides met, this happened:

Lionel Messi is expected to return to MLS action for Inter Miami CF after missing matches against the Houston Dynamo and Charlotte FC.