#4 Michael Conforto
Another San Francisco Giant makes the list. If the Giants fall off the pace, one of Pederson, Wade Jr. or Michael Conforto must find themselves in Houston after the deadline. Conforto got off to a slow start in March/April, but now holds a .248 average with a .790 OPS and a 116 OPS+.
Another lefty, he too would balance the Astros lineup. He's under contract through this season with a player's option for next season, and would likely be the cheapest of the four options listed. He's in the 82nd percentile in walk rate, 66th percentile in barrel rate, 65th percentile in hard hit rate and 61st percentile in xwOBA.
All 53 of his starts in the field this season have come in right field, so he would possibly create a log jam with Kyle Tucker, though he's got 259 career starts in left field.
Conforto is the worst of the four options listed as he does have some history of injuries and is a subpar defender, but if Yordan's injury isn't too serious and if Michael Brantley won't be able to contribute this season, Conforto would greatly help the lineup as a DH.