They'll be taking aim at Target Field at 8 p.m. ET on Monday night (ESPN), as part of the All-Star Week festivities.
Joining Morneau (13 homers, entering Thursday) and Tulowitzki (20) in the NL field are the Marlins' Giancarlo Stanton (21), the Dodgers' Yasiel Puig (12) and the Reds' Todd Frazier (17).
In addition to Donaldson (20) and Bautista (17), the AL field includes the Twins' Brian Dozier (16), the Orioles' Adam Jones (16) and defending Derby champion Yoenis Cespedes (14) of the A's.
Morneau fell short in the NL Final Vote, losing out on his bid for an All-Star roster spot to the Cubs' Anthony Rizzo. But he opted to come back to the Twin Cities, anyway, and the Derby will give him a chance to put on a show for the Twins' faithful, who rooted him on from 2003-13, including his MVP season in 2006.
"I think it's a great story, him going back to Minnesota," Tulowitzki said on the ESPN announcement. "I'm sure the fans will have a lot of fun with it, and so will he."
Morneau has had a resurgent season in Colorado, turning in a .313/.346/.509 slash line. And now he has a chance to build on his Derby profile, having participated in the event twice before and won it in 2008 (outlasting Josh Hamilton, whose first-round performance that year is still the stuff of Derby legend).
Donaldson, meanwhile, will be experiencing the Derby -- and the All-Star festivities -- for the first time. His 20 homers lead all Major League third basemen, one year after he recorded a career-best 24 homers en route to a fourth-place finish in the AL MVP voting. Donaldson can only hope to be as successful as A's teammate Cespedes was last year.
"Hopefully," said Bautista, "this will give us a strong five to go up against the NL, put it to them and put on a great show for the fans of Minnesota."
The league affiliations are particularly important in the first round of what is a revamped Derby.
A new format has been installed this year, as the five players from each league will receive seven outs instead of the usual 10 in each round. In the first round, the player who hits the most homers in each league will receive an automatic bye to the third round (semifinals). The next two players from each league with the most homers will square off against one another in a head-to-head matchup in the second round, with the two winners advancing to the semifinals against the league's top performer from the first round.
The final round will be a showdown between the AL and NL's best. If necessary, the first tiebreaker would allow the finalists three swings apiece.
If you can't wait for the actual Derby, the MLB.com Home Run Derby mobile game is a good way to immerse yourself in the action immediately, with Target Field serving as the setting. The game is available for download on the Apple App Store and Google Play. New for 2014 is Multiplayer Derby Mode, Achievements and Objectives.