Bryce Harper has already experienced the ire of Philly sports fans just two months after finalizing his 13-year, $330 million contract with the Phillies thanks to a booing Citizens Bank Park crowd on Tuesday night.

And, of all people, ‘90s band Smash Mouth took notice.

You know, the guys who sang “All Star,” a song made famous in 1999’s Mystery Men. The ones who covered The Monkees’ “I’m A Believer” for Shrek in 2001.

Those guys.

Apparently, the group is still mad over Harper signing with the Phils instead the San Francisco Giants, who also courted the right fielder ahead of this season.

“Told you not to go to Philly jackass,” the band tweeted from its official Twitter account Wednesday night. “[Giants] fans NEVER boo their own players! You we’re lead by $ only so swim in the sea of boos now!”

Following the Phillies’ 3-1 loss to the Detroit Tigers on Tuesday, Harper told reporters that he would boo his performance as well, saying “I’d do the same thing.” Sportscaster Adam Schein also approved of the booing, saying that Harper “deserved to be booed.” Smash Mouth’s Twitter account took issue with that approach, too.

“Bllsht! Nuture [sic] your players, support your players. That way when they pull through you can feel like you deserved it and you feel like your part of it,” the band wrote online. “Booing makes you the enemy…NOT part of the team.”

Phils fans, naturally, fired back at the group, accusing them of being one-hit wonders and “a band that has not been relevant since the 90s,” as one fan wrote. There are tons more, many not fit to embed here, but Phillies supporters weren’t shy:

Other fans pointed out that Smash Mouth has been doggedly pursuing Harper since the preseason. Back in February, the group wrote online that they had the inside track on Harper’s potential signing with the San Francisco Giants, and claimed that the team’s ownership was not “on the same page” about the deal. The Phillies later confirmed Harper’s signing in early March.

Since their ’90s heyday and early 2000s, Smash Mouth has made a name for themselves on Twitter via various online feuds, some of which have involved other teams and players, like the Oakland A’s, or Gold State Warriors power forward Draymond Green.

The Phils’ leadership, meanwhile, doesn’t seem too concerned with Harper’s flagging performance on the field as of late. As Inquirer sports columnist Bob Brookover wrote following the team’s 7-3 victory over Detroit on Wednesday, Phillies manager Gabe Kapler is “confident” that Harper will improve.

“This is not unusual by any stretch,” Kapler said. “It’s a tweak here or a mental adjustment there, and [the great hitters] roll. This is what is going to happen to Bryce Harper. I’m confident in that.”

As for Smash Mouth, however, this seems to be the way they like it, and they’ll never get bored.