The Rays are not a lock for the postseason at all. Their hell run at the end of this month is going to be a real test for them. The Rays play 10 out of 16 vs the Yanks or Sox to end July into Aug 1. If they are still in the WC lead after that gauntlet, then they are likely to take it to the house. They follow their Aug 1 sox game with an off day then 20 consecutive games vs .500 or worse baseball teams. Their September starts off slow then finished with 8 games vs the LAD, BOS and 2 vs the NYY then close the yr with 3 vs the Jays. If the standings hold and the Yanks and Dodgers clinch by then, the only team fighting them the final two weeks will be the sox.
The Guardians have the easiest path due to their division and they should get healthier with Kluber and Carrasco returning. They come out of the break with 3 vs the Twins. If they take that series, then you have to consider the Guardians as more than just a WC team as they're only 5.5 back of the Twins right now. Then the Guardians go on a joy ride through garbage for 14 games with the Tigers-Royals-Blue Jays-Royals on tap. These teams are so bad that the Guardians could conceivably go 12-2. They have their own hell run completing July and for most of August with the Astros-Angels-Rangers-Twins-Red Sox-Yankees for 20 games in a row, no days off. Their September is mostly a mixed bag. They need to crush the bad teams then survive August to win it.
The Red Sox have a really tough finish to July. They start the post ASB with 3 vs the Dodgers with their rotation aligned. Expect a Buehler-Kershaw-Ryu battle and they'll be looking for blood. The sox get 7 vs the AL shitters then play 14 in a row vs the Rays and Yanks. This is the make or break spot for the Rays and Sox and it takes us past the trade deadline. The sox then come home vs the Royals and Angels before going to Cleveland. Then they come home for the Orioles and Phillies before going on a whacky west coast trip to SD, then Colorado then back out to Anaheim (wtf?). The sox get a day off, come home and play the Twins and Yankees. They then close the season with a mixed bag against possible WC contenders and mostly vs garbage. The 14 in a row vs the Rays and Yanks will go a long way to confirming who the sox are. If they survive that, then the west coast trip always causes issues with the sox. They have a rough road through Sept 1, then a reasonably easy schedule after that.
The A's are the hottest club and the team I have said before is most likely to end up the WC, but their schedule post ASB is difficult. 5 cupcake games out of the break with the Mariners and CWS. Then Twins-Astros-Rangers-Brewers-Cards-Cubs. A 2 series break with the CWS and Giants then back to grind vs the Astros and Yankees for 7 games. They get 6 cupcake games vs the Royals and Giants before coming east vs the Yankees to close August. Their September is a bit easier if the Angels and Rangers fall out of the race with only a 3 game set at Houston standing in their way of a pretty soft September