Wieters will go on to be a stud, but he hasn't gotten comfortable yet. I'd definitely have him on the bench until he starts to get into a rhythm.
As for which 4 OFs to use, it depends on what you need.
Cruz is averaging a home run every other day for the last 10 days, so I'd consider him to be a sure thing to start for you right now (when he cools off, that would probably change).
Holliday's been tearing it up recently too, so I'd keep him in the lineup.
Bay's still raking, so I'd have him in too.
The last spot goes to Crawford. 7/18, 2 HR, 3 RBI, 1 SB, 2 CS (so it's not like he's stopped running), and is going against Bannister, a guy who has gotten shelled 2 of his last 3 outings and has a history of handing out free passes like candy.
Upton's been hot for awhile, but he's 1 for his last 12.
Pierre's been hitting well (though for little production), and he's going against Garland, which will be good for his stats, but I'd still give the edge to Crawford.