I lost a guy that was basically a LRP/swing starter for me as I have 4 guys that can cover most of the games due to good Dur/Sta combinations. I really only have 2 minor league options that are potential replacements, but they are 19 and 20 respectively. I am competing for a title, so if I need to call one of them up, I will do so. My experience says young players don't do well in the majors regardless of their ratings.

Player I lost:
Player Profile: Rio Javier - Hardball Dynasty Baseball | WhatIfSports

Replacement options:
Player Profile: Burch Mancini - Hardball Dynasty Baseball | WhatIfSports
Player Profile: Peter Chang - Hardball Dynasty Baseball | WhatIfSports

not that I know what I'm doing, but I'd call Chang up. He has a slightly better makeup which may help him adjust to the big leagues. Actually, if at all possible, I'd sign a free agent and leave them both in the minors.

We just hit the transaction deadline...not much out there in FA at this point. My inclination is to leave them in the minors as well. I guess I'll take one of my mediocre and rarely used LRB guys and spot start them hoping for the best. I'll have to address that loss because it leaves me with only 6 arms in the pen, but I guess it's better than finding a random SP that won't kill me at this point. Easier to find a mediocre LRB than a quality SP.

Consensus among vets seems to be no such thing as an early call-up penalty to player development. If one of those guys is your best option give him the call-up. He may even develop more under ML coaching. Long relief seems like the perfect place to give a young guy some experience (kind of like real life wouldn't you agree?).

Player Profile: B.C. Acquilino - Hardball Dynasty Baseball | WhatIfSports just finished up his first stint in the bigs during the second half of an ML season in one of my leagues. Somewhat similar ratings to your Mancini. He's 22 y/o but also only has 2 years pro exp. Finished the year with 3.19 ERA, 1.22 WHIP, .239 OAV in 14 starts. But he also had a top 5 defense behind him and a solid pen backing him up.

Maybe a vet knows the answer to this but one benefit of a call up could be getting Mancini to drop his P4. At 28 though it may be too high to drop. I don't know what the cut-off is.

Tired of losing, I called these guys up at 21(2nd year). Mostly because they were my best. Neither slumped or suffered because of it.

Player Profile: Deivi Galvez - Hardball Dynasty Baseball | WhatIfSports
Player Profile: Edgmer Zorrilla - Hardball Dynasty Baseball | WhatIfSports

Brought this guy up 1/3 into his first full season (age 19). He struggled because his hitting ratings weren't particularly good. But his power made for a decent bench option, and my ML HC was vastly better than any other HC in my system. OVR went up 10 from ST-ST and is up another 3 in less than half his age-20 season. His hitting has improved by what his ratings suggest it should: .174 vs. LHP and .298 vs. RHP (44-71 splits). 15 HR in 150 AB vs. RHP (93 power)

https://www.whatifsports.com/HBD/Pages/Popups/PlayerRatings.aspx?pid=7596510

I've decided to give this guy the first shot at spot starting. His first start will be in the AM game.

Player Profile: Del Perez - Hardball Dynasty Baseball | WhatIfSports

His history is fairly mediocre, but statistically better than the guy he's replacing. I'm not willing to trust the young guys based on my personal experiences in spite of some people's experiences that state otherwise.