It's not necessarily about the physical discomfort battering the White Sox top pick from the 2009 First-Year Player Draft. It's more the mental anguish affecting Mitchell, after his 2010 season basically came to an end before it started when he tore a tendon on the inside of his left ankle Friday.
In 1992, Guillen suffered torn ligaments in his right knee during a game on April 21 against the Yankees. He missed the remaining 150 games but bounced back in 1993 after following the rehab process laid out for him.
And it wasn't always easy to follow that rehab, according to Guillen.
"Rehab is a funny thing," Guillen said. "One day you feel like, 'I'm ready to play tomorrow,' and then you show up the next week and you can't even walk. You have to be patient because it's a process to heal. Go do everything the right way and be patient. It's the best thing you have.
"You lose a year and the worst thing about it is to be [impatient]. You see one year go by and you miss that year and you don't know how good you are going to come back. Make sure you do every day what you are supposed to do and don't worry about what's going to happen next.
"That's hard to do, very hard to do it," Guillen said. "Especially in the summer, when everyone is out having fun playing and you are not. Mentally, you have to prepare yourself very well."
Mitchell suffered this devastating injury running into the left-field wall to make a catch on Juan Rivera's fly ball to start the sixth inning of Friday's 10-7 win over the Angels in Tempe, Ariz. Mitchell had just entered the game as a defensive replacement and was only part of the contest because of split-squad action, with part of the White Sox playing the Cubs in Las Vegas later that Friday. Mitchell was reassigned to Minor League camp Wednesday.
The White Sox announced Saturday that Mitchell will be evaluated on Monday in Scottsdale and then is scheduled to undergo surgery on Tuesday at the Greenbaum Outpatient Surgery Center. Dr. John Nasser, a foot and ankle specialist, will perform the procedure.
A rehabilitation schedule and recovery time will be set following surgery.
Juan Pierre got to know Mitchell during Spring Training, with the veteran White Sox leadoff man's locker situated next to the 21-year-old. Pierre actually served as a mentor to Mitchell, who has been touted as Pierre's possible replacement in a couple of years.
Missing the season certainly will hamper the development process for Mitchell, who made a lasting impression during his stint in Arizona but still would have been starting his first season focused solely on baseball. Pierre believes the injury won't knock out this hard-worker and five-tool talent, who played both football and baseball at Louisiana State.
"Maybe it will be a blessing in disguise, where he can sit and watch the game and learn that way," Pierre said. "All he needed was to go out and play. He has the tools, all of them. He has everything, but just needed the repetition.
"Remember, he's 21 and he has a lot of time to get back and get healthy. He's in shape so he won't have a problem getting back. It's a tough blow, but hopefully he can rehab and get back sooner than expected. Hopefully his spirits will stay up."
Guillen plans to talk with Mitchell, reinforcing the point of just taking the rehab process step by step and not trying to map out his playing future before he fully heals. Guillen also stands as proof that you certainly can come back from such a tough setback without losing much, as he posted a .280 average over 134 games in 1993, matching a career high with four home runs.
Of course, Guillen's injury came after he had posted seven solid big league seasons. The big league talent is there for Mitchell, though, and Guillen believes the perseverance to return is, too.
"When you lose a year, you have to work a little harder to get this time [back] you lose," Guillen said. "Just go out there and battle. Every day is going to be a battle until you come back, but when you come back, you will feel the satisfaction about the waiting is worth it. I never had a problem after my surgery."
"His baseball instincts are there and you can tell he has all the tools," Pierre said. "He was a guy you can see had that baseball feel about him, and he was just about to get going."
Scott Merkin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.