FORT MYERS, FLA. – Max Kepler's 2016 season included game-winning home runs, acrobatic catches and record-breaking performances. A right fielder with a smooth, lefthanded stroke, he appears to be part of a young core of players that can lead the Twins back to winning baseball.

Not so fast, according to a source.

Kepler also has shown that he is strikeout-prone, is susceptible to lengthy slumps and has botched plays in the field. He's a potential gem, but needs plenty of polish.

That source is Kepler himself, and that blunt self-assessment is fueling his preparations for 2017.

"I'm aware of everything that happened," said Kepler, the Twins Minor League Player of the Year in 2015. "I'm going to be honest. I don't beat around the bush. I know what to work on."

Kepler was called up from Class AAA Rochester in April but was sent back near the end of month. He got another shot in June, and began to show why the Twins signed him out of Germany in 2009.

His first major league home run came June 12 — a three-run, walk-off shot against Boston, becoming the fourth Twin to win a game with his first career homer.

Kepler hit .242 in July with eight home runs and 23 RBI in 25 games. That included a club rookie record seven RBI against Texas on July 2. That propelled him into August, which began with a three-homer game in Cleveland. He went 8-for-16 with four homers and 10 RBI in the four-game series, and by the end the Indians began to intentionally walk the rookie.

But his season peaked about that time, as scouts from opposing teams sharpened their pencils.

"No more fastballs," Kepler said.

He hit .194 with two home runs and 11 RBI over his final 40 games to finish with a .235 average with 17 homers and 63 RBI.

"I've never hit that low of an average," Kepler said. "I struck out a lot. So I need to improve in a lot of areas and not worry over things I'm not in control of. I let a lot of stuff get in my mind, especially the second half."

Kepler runs well and has a good arm, but he committed seven errors in 113 games. He attributed that to occasionally taking his eye off the ball to check baserunners, which led to misplays. Most notably, on June 15 in Anaheim, he overran a fly ball, enabling two Angels runs to score.

"I wasn't happy about that either," Kepler said. "I made more errors than I did in my minor league career [in a season] which, again, that's not my game. I let my emotions get the better of me."

Byron Buxton, a minor league teammate of Kepler's since 2012 at rookie league Elizabethton, has heard Kepler call himself out before.

"That's what I'm I used to," Buxton said. "He's been like that since I met him. And he knows if he's not doing some things, I get on him, and the same with me. We have that connection where we can talk to each other and get on each other."

Kepler's challenge is to be an impact player more consistently. He is using camp to take better at-bats and use the whole field more. He is also addressing his defense. Michael Cuddyer, who was in camp recently as a special instructor, worked with him on running down balls hit into the corner, spinning and firing to second. Kepler has a tendency to bounce on his back leg before throwing, which costs him time. Cuddyer wants him to launch toward second.

Kepler began spring training games hitless in 10 at-bats before smacking two doubles to right Saturday against Toronto. He was 0-for-3 on Monday against St. Louis, lowering his Grapefruit League average to .125.

Twins manager Paul Molitor didn't realize Kepler was off to a slow start.

"I think his at-bats have been good," Molitor said. "He got a little feedback [Saturday]. He smoked the ball to right field. He's looked really good, overall, to me, He's really picking up on the details on defense. He has a more aggressive mind-set and is trusting his swing. So far, I think he's had a good camp."