CHICAGO -- Like many Cubs fans, actor John Cusack breaks into a sweat every time he hears Javier Báez's name in a trade rumor. He's had more practice than he'd like with this routine the past few years, but it is only making it sweeter to watch Baez blossom into a special player.
Cusack, a huge Chicago sports fan, was a believer in the Cubs infielder back when he was so raw that you wondered if he would develop into more than just a guy you'd want for the Home Run Derby.
At the end of the Cubs' Hot Stove activity last offseason, Cusack was as excited that Baez was still in the organization as he was about newcomers like Jason Heyward, John Lackey and Ben Zobrist..
"My instincts say [that] could be the best non-move they could make,'' Cusack, who grew up loving how Jose Cardenal always ran hard down the line, texted me. "I have a feeling he can become a superstar. When his bat explodes …''
And Cusack is right. The upside to Baez is enormous, even if he remains only a semi-regular for baseball's winningest team. The 23-year-old from Puerto Rico (via Jacksonville, Fla.) was in the lineup at second base on Friday after coming off the bench to play third late in Thursday's 11-inning victory over the Cardinals.
Baez's bat still runs hot and cold, but he's so skilled in the field and on the bases that he's making major contributions to baseball's best team on almost a daily basis.
It's a blast to watch Baez play. Sometimes he even seems to amaze even himself.

Cubs manager Joe Maddon slipped Baez into Thursday's game with a double switch in the ninth inning, when he brought in closer Aroldis Chapman in a 3-3 tie. The Cardinals' hitters were clearly dialed up to hit the first strike they saw, because Jedd Gyorko and Greg Garcia both lined fastballs (clocked at 100 mph and 102 mph, respectively) to Baez.
Gyorko, a right-handed hitter, pulled a 105-mph rocket directly at Baez, who caught it out of self-defense. Garcia, a left-handed hitter, was late with his swing and didn't make quite as solid contact, but the ball still came at Baez in a hurry. He grabbed it off his shoetops for the second out, then flashed a big smile to the dugout and even umpire Dan Bellino, the closest witness.
"He's a game-changer on defense," Maddon said earlier this month. "There has been more of a consistent approach to his game at times, better than I'd seen last year. You have to take the bad with the good."
Baez was selected in the first round of the 2011 Draft as a shortstop, and he only started playing some second and third base in 2014, when he reached Triple-A Iowa. He's played 92 games this season, including 65 starts spread between third base (28), second base (24), shortstop (12) and first base (1).
"I've seen him do a little bit of everything,'' Cardinals manager Mike Matheny said. "He's played some good defense, whether on the right side of the infield or at third. I've seen him make nice plays. He moves well, has a lot of power, doesn't get cheated when he swings.''
No, he doesn't. But through hard work at every level from instructional league to a trip to the Puerto Rican Winter League, Baez has figured out how to use his otherworldly instincts for the game he loves.
Baez is still on pace to strike out 112 times in 416 at-bats, but these days he's capable of beating you with a bunt single as well as monstrous home runs. His combination of power and strikeouts has defined him as recently as 2013, when he hit 37 homers and struck out 147 times in 130 games between Class A Advanced and Double-A, but he's not that hitter anymore.
Baez is hitting .275, and he blasted his 12th home run in the Cubs' 13-2 victory Friday afternoon -- a no-doubt drive over the left-field wall off Jerome Williams.
Baez dominated left-handed pitchers in the first half of the season, then began hitting right-handers better after the All-Star break. That may have helped persuade Theo Epstein from paying the high price it would have cost to get another left-handed-hitting option like Josh Reddick or Jay Bruce before the non-waiver Trade Deadline.
Baez was 15-for-39 with two homers and eight RBIs in 12 games in late July, but he was in a 3-for-31 slump entering Friday's game.

Maddon knows that's the inconsistency you live with in developing young hitters.
"There's a week to 10 days where he'll shorten up [his swing] and use the entire field,'' Maddon said. "Other times, he's pretty much John Daly.''
Rangers manager Jeff Banister was a bench coach for the Pirates two years ago when the Cubs promoted Baez, then 21, for the last two months of the season. He hit nine home runs, but batted only .169 with a strikeout rate of 41.4 percent. Baez made some spectacular plays in the field, but he was charged with 10 errors in his 52 games.
It's safe to say Banister has been impressed with how Baez has smoothed out his game.
"Yeah, he's a real nice player,'' Banister said when the Rangers visited Wrigley Field in July. "It's pretty impressive. He's grown up from the first time I saw him, when he first came in. He's still got a big swing, but [he's] a lot calmer. It's been pretty impressive to watch him.''
Banister believes the Cubs did the right thing by using the end of an 89-loss season to give Baez his first taste of the big leagues. It showed him what he needed to work on, and he's taken it from there.
"When you can kind of self-assess and decide what's going to make you better, and you can put that in motion and work on it, and execute it, it makes you a good player,'' Banister said. "He's got an opportunity to be a really good player.''
Baez has range, a strong arm and a fearlessness that allows him to go face first into the stands after balls. He has some of the quickest hands around, and can make tags few other infielders ever make.
When Baez is on base, he can avoid tags with moves worthy of the Cirque du Soleil acrobat. It's a well-rounded skill set that always argues for Maddon to find room for him in a lineup that has Kris Bryant, Addison Russell and Zobrist as infield regulars.
Baez has generated 2+ WAR in his super utility role, rolling toward a three-win season. That's the tip of the iceberg in terms of his potential, which is why Epstein has always had him on his untouchables list in his quest to trade for another controllable arm like Josh Beckett, who was 26 when the Red Sox acquired him from the Marlins.
Finding playing time for Baez doesn't figure to get any easier in the future, not with Kyle Schwarber expected to return to left field for the 2017 season. But Maddon has never been known to waste his resources, and he's not going to start with a 23-year-old who can do it all.