There are other grunts to do that this season. But the affable 22-year-old from Cincinnati is still working his way up the pro sports pecking order.
Which is why Hagglund is wearing No. 6 this season after giving up No. 17 to newly acquired star striker Jozy Altidore.
A text from the club informed Hagglund of the change.
To be fair, all the numbers favour Altidore.
The U.S. international has a seven-figure salary that starts with a four. Hagglund's pay last season also started with a four, but was followed by a mere four numbers (US$48,500).
Altidore has 856,000 Twitter followers. Hagglund has 1,860.
It should be noted that Hagglund, a good sport whose face is fixed in a permanent smile, isn't complaining one bit about the number switch. He's not expecting Altidore to leave him an Aston Martin with a bow on it in the Toronto FC parking lot.
"If he does, that's great," Hagglund joked. "If he doesn't, it's (just) a number.
"Just put some goals in the back of the net and I'll appreciate that."
Hagglund, who wore No. 17 all four years at Xavier University, chose No. 6 because it's a "good centre back number." It's also his new wife's favourite number. His favourite number is nine, which is a six upside-down.
"A number is a number. It's how you play, that's what matters," said Hagglund.
The six-foot-one defender had a busy off-season. He got married back home and honeymooned in Jamaica.
The couple have now moved into Hagglund's old apartment.
"It looks a lot nicer now," he said with a giggle.
Hagglund couldn't wait to get back. He arrived in Toronto three weeks early and has been working out with the coaches prior to the official start of camp.
Taken 10th overall in last year's SuperDraft, Hagglund's athleticism and confidence quickly won over former manager Ryan Nelsen.
Greg Vanney, who took over after Nelsen was fired, said he too was pleasantly surprised by Hagglund, who started 23 games for a Toronto team that was thin on the backline.
"I think we relied upon him probably a little bit more than we should have," said Vanney, who like Nelsen is a former defender himself. "And in fairness to him, he stepped up and he did a good job."
But there is plenty more to learn, added Vanney.
"This is not going to be a defining year for him or anything like this. It's another year for him to work through the process of being a great player which is where he's going to end up at some time."
Toronto has brought in Polish international Damien Perquis to partner Scottish veteran Steven Caldwell at the heart of defence. Hagglund, a threat in the air who can also play right back, will be learning from both.
Toronto added to its depth at the heart of its defence by trading for Eriq Zavaleta and drafting Canadian Skylar Thomas and Clement Simonin.
Hagglund isn't the only Toronto player to give up his number to a newly acquired star. Defender Doneil Henry, since moved to England's West Ham, gave his No. 4 to Michael Bradley and wore No. 15 instead last season.
Vanney never had to given up his number during his playing career. But, after starting with No. 18, he had to wait until No. 3 came open.
New signing Sebastian Giovinco will wear No. 10 when he lands in Toronto.
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