"It's been a grind," Morrison said. "Playing through pain. Not playing. Wishing I was playing. Rehabbing. I've been rehabbing on and off for two years now. To put it behind me and all that stuff will be good."
Morrison began his rehab assignment with Class A Jupiter on Monday, initially being used as the designated hitter for the Hammerheads. On Wednesday night, he played first base for nine innings -- going 1-for-5 at the plate.
Thursday was a 10:35 a.m. ET game in Jupiter, and Morrison was given the day off. He expects to play nine innings at first base on Friday and Saturday. Barring any setback, Morrison will head to Double-A Jacksonville on Sunday for at least a few games.
Morrison is eligible to be reinstated on May 30, but he admits it will likely be a few days afterwards.
"I don't think the 30th is a realistic date," Morrison said on Thursday. "I don't think it's because of the knee, though. It's more because of the at-bats and not playing back-to-back days."
Thus far, Morrison is 3-for-13, and he is still in the process of getting his timing down. By rule, position players can spend up to 20 days on rehab assignment, and Morrison could remain in the Minors through June 9, when the Marlins are at the Mets.
In his long road to recovery, his first step was getting healthy. Next, is getting in game shape. Morrison noted his knee was a little stiff on Thursday morning, which was expected after being on the field for nine innings.
"It's a little stiff from playing last night, but that is expected when you get up at 8 in the morning," he said. "Even if I didn't have surgery, it would probably be stiff."
In many ways, the rehab assignment is Morrison's Spring Training.
It's been a frustrating, injury-plagued season for the Marlins, who have been hurt by ailments. Morrison, for instance, is one of three Miami first basemen currently on the DL. All three are on rehab assignment in Jupiter.
On Thursday, Casey Kotchman (right hamstring strain) was used as the designated hitter for the Hammerheads. Joe Mahoney (right hamstring strain) was scheduled to play on Thursday. But his hamstring remains a little tight, and he is being held back another day or two.
In an injury-ravaged season, the Marlins are eager to get some of their players back. Nathan Eovaldi, on the 60-day DL with a right shoulder inflammation, is slated to make his first rehab assignment start for Juptier on Saturday. Eovaldi threw a side session on Wednesday, and he is also eligible to return on May 30.
When ready, Morrison will take over at first base.
"I still have never seen this guy play in any games," manager Mike Redmond said. "I've heard a lot about him, and I'm probably like the fans, I'm really excited to see him play."
Morrison last appeared in a big league game on July 28, 2012. But he was never fully healthy the whole season.
Initially, Morrison had surgery to his right knee in December 2011, and he dealt with discomfort up until he was shut down last July. In an injury-shortened 2012, the left-handed-hitting first baseman hit .230 with 11 home runs and 36 RBIs in 93 games.
Morrison's most productive big league season came when he was a rookie in 2010. Called up in July, he batted .283 with a .390 on-base percentage in 62 games.
In 2011, Morrison had his ups and downs, batting .247 with 23 homers and 72 RBIs in 123 games. But late in the season, he crashed his knee into a wall at Pittsburgh, which started his knee troubles.
After all Morrison has gone through, he is relieved to be close to returning.
"More than anything, it's going to be fun to be back in the big leagues," Morrison said. "I don't think the knee will be an issue. It will be exciting to be back in the big leagues, competing and knowing all the hard work wasn't for naught."