A two-time All-Star in the late 1990s with the Kansas City Royals, Rosado has not pitched in the major leagues since 2000 and is now attempting to come back from two shoulder surgeries with the Mets.
After Rosado's stretch of success with Kansas City, in which he went 37-45 with a 4.25 ERA for some pretty mediocre or worse Royals clubs, his career came to a grinding halt with an assortment of aches and pains plaguing his pitching shoulder.
Rosado nearly attempted a comeback with the Cincinnati Reds two years ago, but deemed himself not ready to compete at that time.
Now, after a winter of rehabilitation and still at the relatively young age of 30, Rosado may have the strength and command to get professional hitters out once more.
"This year I've been playing catch, I've been throwing bullpens and have taken the whole year off with no surgery, no nothing," Rosado told MLB.com in January. "Everything has come out good."
Background: A 6-0, 185-pound lefthander, Rosado has his share of big league experience. From 1996 through 2000, Rosado appeared in 125 games (112 starts) with the Royals.
His best season was his 1999 campaign, in which Rosado finished fifth in the American League with a 3.85 ERA. In 33 starts that year, Rosado ate up 208 innings and struck out 141 batters. He was also the winning pitcher in the 1997 All-Star Game.
Outlook: The Mets aren't exactly pinning hopes on Rosado's comeback, as they have a ton of left-handed pitching competing for roster spots this spring (although, some of the talent could be considered questionable).
The Mets have little to lose by inviting Rosado to camp, and you never know when a southpaw with a live arm could come in handy.
Rosado, whose starting days are over, may not fit that description to a tee, but he said earlier this winter that he'd be willing to pitch at any level to work some kinks out.
That could interest the Mets, who are a little low on quality left-handed relievers this season. Felix Heredia had a 6.28 ERA in 47 games for the Yankees last season, and the non-roster invitations of Scott Stewart and Mike Matthews may or may not pan out.
Blake McGinley is coming off of a promising minor league campaign in which he was sent to the Arizona Fall League, but he falls victim to a numbers game in which Korean lefty Dae Sung Koo is likely to make the major league roster, as should Heredia.
Still, you never know who could be this year's Jose Parra, coming out of nowhere to help out the big league team. If Rosado shows arm action, there's no reason it couldn't be him.