There will be a flurry of activity in the American League East later this week when the calendar turns to September on Friday.
Rebuilding teams such as the Blue Jays, Rays and Orioles will take advantage of the expanded rosters by calling up some of their more promising prospects. The Yankees and Red Sox are simply looking to get healthy as they embark on a final push for the postseason, and there's a clear need to get some of their prominent players back into the lineup.
Here is one important storyline to follow for each team in the division as clubs prepare for the final month of the regular season:
Blue Jays
Move to watch: The summer sale continues
The Blue Jays were one of the most active teams in the days leading up to the July 31 non-waiver Trade Deadline, and there's a good chance that general manager Ross Atkins will make another move before the end of August. Josh Donaldson's health status continues to hang over the club, but even if Toronto can't move him before Friday at 11:59 p.m. ET, the club will continue to explore the market for some of its other veteran players.
Curtis Granderson, Marco Estrada, Kendrys Morales and Justin Smoak are among those who cleared waivers and can be traded to any team. Reliever Tyler Clippard is available as well from a Blue Jays team that is actively shopping almost all of its veterans as the club continues to embark on a rebuild.

Orioles
Move to watch: Catcher Chance Sisco's promotion
The rookie has been up and down all year, a disappointment after making the Opening Day roster in what was supposed to be his year. Once one of the O's top prospects, Sisco is expected to be part of the team's September roster expansion. But how he will fare this fall and beyond remains a question.

Rays
Move to watch: Austin Meadows' promotion
The Rays acquired Meadows in the deal that sent Chris Archer to the Pirates. Though he has played at Triple-A Durham since the trade, he is expected to be called up in September. Before coming to Tampa Bay, Meadows was considered one of the best outfielders in the Minor Leagues. He made his debut with Pittsburgh this season, hitting .292 with five home runs and 13 RBIs in 49 games.

Red Sox
Move to watch: The return of Eduardo Rodriguez
The lefty makes his return to action this weekend after missing the past six weeks with a severe sprain in his right ankle. Rodriguez had emerged as a key cog in the Red Sox's rotation before the injury, and his return should make the staff that much deeper down the stretch.
A healthy and effective Rodriguez would give Boston a strong four-man rotation for the postseason and allow Nathan Eovaldi to move to the bullpen, where his stuff might play better than it does in the rotation. In the past, Rodriguez has been tentative when he returns from injuries. But manager Alex Cora thinks Rodriguez has matured greatly this season and will be able to pick up where he left off.

Yankees
Move to watch: Activating Didi Gregorius and Gary Sanchez
Aaron Boone has said that he expects both Gregorius and Sanchez to be active for the upcoming West Coast trip, which begins Monday in Oakland. Those additions should serve to lengthen a lineup that has withstood the extended absence of Aaron Judge, whose initial timetable of three weeks to return from a fractured right wrist has turned out to be overly optimistic. Sanchez homered in his first Triple-A at-bat on Monday, and the Yankees believe there is still time for him to reclaim his 2017 form.