The American League East is always one of the most competitive divisions in baseball, and 2021 is shaping up to be no different. With the defending AL champion Rays, the perennially contending Yankees and the ascendant Blue Jays, three playoff teams return to the division alongside the new-look Red Sox and the improving Orioles.

All five clubs have been active this offseason, with Toronto signing headliners George Springer and Marcus Semien, New York bringing DJ LeMahieu back and big-name pitchers both exiting and entering the division via free agency and trade. What should look fairly familiar, however, is the situation at corner infield, where some of the AL East’s biggest impact players make their living.

Here’s a look at what we know, and what we don’t, about the corner spots in the AL East.

Blue Jays
The known:
Vladimir Guerrero Jr.’s offseason has been spent campaigning for a return to third base, and while the Blue Jays are leaving the door open to that possibility, it’s clear that Guerrero’s long-term home is first. If Toronto can field a stronger lineup by playing Guerrero at the hot corner the odd time through the season, that would be a win for the club and would give it some more versatility. But Semien and Cavan Biggio are capable of handling third, too. Biggio would be the starting third baseman if the season started today, with his throwing arm being the main challenge to watch in Spring Training, while Rowdy Tellez has the inside track on designated hitter reps while spelling off Guerrero at first. Tellez put up an .886 OPS over 35 games last season, and he would give manager Charlie Montoyo a powerful bench bat, too, on days he’s not in the starting lineup.

The unknown:
Outside of their starting rotation, third base might still be the Blue Jays' biggest opportunity for an upgrade. Biggio could hold his own there, but if Toronto were to find a veteran option at third, that would allow it to move Biggio around the diamond, with his advanced baseball instincts making him playable at nearly every position. Just like the rotation, this can be sorted out at some point in the season leading up to the Trade Deadline if the Blue Jays find a better opportunity, but having Biggio in that utility role would be a luxury for Montoyo and still allow Biggio to see a starter’s share of reps. Beyond 2021, Toronto has No. 2 prospect Austin Martin and No. 3 prospect Jordan Groshans on the way to join this talented young infield, so if the Blue Jays do add at third, it can be a short-term solution. -- Keegan Matheson

Orioles
The known:
After missing all of 2020 undergoing treatment for colon cancer, Trey Mancini is expected to return to his natural position this season and serve as the Orioles' everyday first baseman. That’s the plan as the roster is currently constructed, with Anthony Santander having emerged in right field and exciting No. 5 prospect Ryan Mountcastle having shown he can handle left. Chris Davis remains in the fold in a reserve role. Across the diamond, Rio Ruiz gets first cracks at third base after showing improved power in '20, but he hit just .229/.299/.393 over the past two seasons.

Utility options Pat Valaika and Richie Martin could also see time at third, while Valaika can play first as well.

The unknown:
If the Santander trade rumors prove true, Mancini could bounce back and forth between first base and right like in the past, freeing up more at bats for Davis. Mancini’s health also qualifies as an unknown given the severity of his condition, though he’s experienced no setbacks. Ruiz could face more competition at the hot corner than at any point in his Orioles tenure, courtesy of No. 26 prospect Rylan Bannon, who is expected to get a long look this spring. It’s not difficult to see the right-handed-hitting Bannon forming a platoon with either Ruiz at third or Yolmer Sánchez at second base. -- Joe Trezza

Rays
The known:
The Rays should have a lot of options at both corner-infield spots from the start, and they could add more later in the year. They’re bringing back three players who saw a lot of time at first base last season: Ji-Man Choi, Mike Brosseau and Yandy Díaz. They’ll also return four players who played third a year ago: Díaz, Joey Wendle, Brosseau and Yoshi Tsutsugo. Choi, Wendle and Tsutsugo are left-handed hitters, while Brosseau and Díaz bat right-handed. That gives manager Kevin Cash plenty of room to be creative and adjust Tampa Bay's lineups based on matchups.

Díaz was excellent early last season, hitting .307 with an .814 OPS in 34 games, before he was sidelined by a strained right hamstring. The versatile Wendle also hit well, batting .286 with a .777 OPS in 50 games, and Brosseau thrived against lefties and delivered a huge moment in Game 5 of the AL Division Series. Choi took a step back offensively last year during the regular season, while Tsutsugo hit just .197 in his first Major League campaign.

The unknown:
Just how will Cash deploy all those corner infielders? There are a lot of questions the Rays must answer.

How will Cash move Wendle and Brosseau around the infield? How will he balance Díaz and Wendle at third, with Wendle having been the preferred starting option during the postseason? Where will Tsutsugo get his at-bats? Brandon Lowe is expected to do some work at third base, so how does he fit into all of this? Can the Rays count on Choi to bounce back to his previous form after hitting just .230/.331/.410 last season? Is first/third-base prospect Kevin Padlo the next man up if they have a need at either spot, or could he force the issue before then? And if Willy Adames remains at shortstop, will the Rays consider moving around top prospect Wander Franco -- whether it’s to second, third or elsewhere -- if he’s ready for his Major League debut at some point this season? -- Adam Berry

Red Sox
The known:
The surest thing of all at the corners is that Rafael Devers will be in the lineup nearly all of the time. The left-handed-hitting third baseman was on the verge of becoming an elite player in 2019, when he had a monster year. However, the delay in Spring Training and the subsequent 60-game season seemed to set him back in ’20. Devers wasn’t as consistent on offense and he struggled mightily at times on defense. Look for Bobby Dalbec, the power-hitting prospect who excelled in his late-season opportunity last year, to go in as the starting first baseman. If Dalbec struggles, the Red Sox still have Michael Chavis around as insurance.

The unknown:
Can Devers tighten up on defense? The Red Sox hope that the return of Alex Cora as manager will lead to Devers rediscovering his 2019 form. Cora has always known the right buttons to push with him. If Devers continues to have problems on defense, here is an interesting question: Would Boston consider having its corner infielders switch positions? Dalbec was a highly regarded defender at third coming up through the Minors. Chavis can also play both positions, but he needs to be more consistent at the plate to stay in the mix. Will chief baseball officer Chaim Bloom try to sign a left-handed or switch-hitting bat to complement the right-handed-hitting Dalbec at first? -- Ian Browne

Yankees
The known:
First baseman Luke Voit and third baseman Gio Urshela project to be vital parts of the Yankees' batting order, coming off a season in which Voit led the Majors in homers and Urshela once again ranked among the league's most productive third basemen. Voit's 22 homers came after the slugger improved his training regimen, using the shutdown to drop about 15-20 pounds. He's also running in spikes pain-free after dealing with plantar fasciitis for much of the 2020 season. Third base remains Urshela’s job to lose after two productive seasons.

The unknown:
Urshela underwent surgery in October to remove a bone spur from his throwing elbow. While Urshela is already running, hitting and throwing, he probably will not play in the spring's first exhibitions. Urshela should be ready for Opening Day, but his early absence figures to mean increased reps at the hot corner for Miguel Andújar, whose role on the club has been uncertain for two years running. Mike Ford is also vying to make the team as a lefty option at first base, but it's unclear how much playing time he could get if Voit is healthy. -- Bryan Hoch