The Arizona Diamondbacks have been the best team in baseball for the past month. Their 18 wins since July 12 are the most in the majors and have shot their Fangraphs playoff odds from 40% to 86.1% in that stretch. Sunday saw them add a massive insurance arm to their rotation in starting pitcher Merrill Kelly, who had a shoulder injury that has kept him out since April. The Diamondbacks are on their way back to the playoffs and Kelly says coming back from injury has been a good time.

“I had some fun,” Kelly said to David Brandt of the Associated Press. “Obviously feels good to be back with the boys and be part of the good baseball they're playing.”

Kelly's return was stellar in Sunday's finale against the Philadelphia Phillies. He threw five innings, allowing just three hits, two runs, and 85 pitches. He's coming off a career year in 2023 that included four excellent starts during the playoffs. The Diamondbacks need Kelly to continue that form to make another run.

It's hard to not be having fun with the Diamondbacks of late. They became a fan-favorite during the playoffs as they beat the big-market Dodgers and Phillies on their way to the pennant. Then, after a tough start, they've put together a ridiculous month to challenge for a division title.

Diamondbacks' playoff expectations

Arizona Diamondbacks pitcher Merrill Kelly (29) throws against the Philadelphia Phillies in the first inning at Chase Field.
Rick Scuteri-USA TODAY Sports

If the season ended after Sunday's games, the Diamondbacks would face the San Diego Padres in the Wild Card series. The Padres have been equally as good since the break and would set up a phenomenal first-round series. That makes the division race very interesting.

If one of the Diamondbacks or Padres catches the Dodgers, it will create the most interesting Wild Card series in its short history. The Dodgers added Shohei Ohtani to their star-studded lineup and it has worked out perfectly. He is on his way to a third Most Valuable Player award despite not throwing a pitch to this point. The Dodgers have struggled recently though and could be caught.

Once the playoffs begin, the Diamondbacks have already shown that they must be taken seriously. Even after an 84-win campaign a year ago, they beat the Dodgers and Phillies to win the pennant. They have made marked improvements this season and can repeat as pennant winners.

The offensive side of their team is led by second baseman Ketel Marte. After avoiding serious injury, Marte is set to finish off what has been a great season. He is hitting .299 with a .932 OPS and a 157 OPS+. He's putting together an MVP-type season that has been squashed by Ohtani.

Kelly's return adds a proven arm to a young rotation. He slides in very nicely as the second arm behind ace Zac Gallen. They made a big splash in signing Jordan Montgomery after he beat them in the World Series with the Texas Rangers. That has not worked out, as he has a 6.74 ERA and a 65 ERA+ in 17 starts.

Merrill Kelly is having fun as he comes back to the hottest team in baseball. The Diamondbacks will be a fun team to watch once again in the postseason with Kelly anchoring their rotation.