As the calendar shifts to April and people shed winter coats for spring attire, the NBA world is heating up as well. With the postseason less than two weeks away teams are rounding into form and preparing to make their run at the Larry O’Brien Trophy.

In the Eastern Conference for the last six seasons, there has only been one name that has mattered: LeBron James. The team that has James in their lineup has represented the East for the last six years and despite inner turmoil and copious amounts of subtweeting, the Cavaliers are once again prohibitive favorites to make it to the Finals this year. While there is no denying that the Cavs would and should be favored, that does not mean that the rest of the East is just going to take their ball and go home.

There are two teams that could pose a major threat to the defending champs if they were to matchup in a series.

The first is the Boston Celtics, who after much posturing stood pat at the trade deadline and currently hold the number one seed in the East. Boston has struck gold with head coach Brad Stevens, who maximizes the talent on the roster like few coaches in the game could. The reason the Celtics have gone from a nice story to a potential championship contender has been the play of point guard Isaiah Thomas. The diminutive superstar is one of the most entertaining players in the league, seemingly creating space out of thin air to get his shot off while surrounded by giants. His fourth quarter heroics have propelled the Celtics all season, as no moment seems too big for Thomas.

The Celtics also have numerous wing defenders to throw at Kyrie Irving and LeBron James. Avery Bradley, Marcus Smart, Jae Crowder, and Jaylen Brown are all very good defensive players capable of making life difficult for Cleveland’s two superstars. If the Celtics can avoid being crushed on the boards (they rank 26th in rebounding percentage, according to they have a shot at knocking off Cleveland.

The other team that could give the Cavs headaches is actually the Milwaukee Bucks. One thing that has bothered Cleveland consistently throughout LeBron’s return has been length and athleticism. The Cavs have a host of veteran players who, while effective pieces around the LeBron, are not the most spry bunch. The Bucks boast several lengthy defenders, chief among them Giannis Antentokoumpo. Milwaukee’s Greek sensation is one of the few players in the league who has a prayer of matching up against LeBron while still being able to contribute offensively. Even Khris Middleton could see some duty on James, although coming off his injury and with his slighter frame he might have a tough time slowing him down.

Rookie Malcolm Brogdon has proven that he is a more-than-capable defender, and he more than likely would be tasked with guarding Irving. That is a daunting assignment for anyone, let alone a rookie in his first postseason, but Brogdon has shown throughout the year that he is far from a typical rookie. The Bucks may not have the fire power to knock off Cleveland, but they the pieces in place to make the Cavs sweat in a seven game series.