I would echo Roger’s advice, and here’s why.
Roger has extensive experience with youth baseball - especially pitching. He’s been involved with youth baseball and is pro active in the right way to experience this game, and for all the right reasons.
Ok, now for my take on your question - please don’t take this personally, nor are my remarks in any way negative to your ambitions of bringing a quality game to your youngsters on the club.
So… here’s my take. The age group that your coaching is very young and very multidirectional at times. I say this because I’ve sat with the lawn chair crowd - not in the coaching ranks of youth baseball, and I’ve watched a lot of men like yourself trying to do the best they could. Now here’s the rub - these youngsters will never meet your expectations, nor will they meet the expectations of their parents. They’re young, full of energy, uncontrollable before and after your time with them, and the club’s makeup is not of your choosing - but that of others. So you’re probably working with what you have, the best you can, and right out of the starting gate.
I admire your wanting to conduct a bullpen session - and asking that question is really forward thinking. Now for all the planning and wanting… your league may have limits and time framings that might conflict with your ambitions. Hence, the advice from Roger.
There for, a FORMAL bullpen session may be construed as PITCHING, whereas playing catch MAY NO. Do you see where I’m going with this? Simply tossing the ball around, WITH THE ENTIRE TEAM, not a stand alone pitching practice, can be just a team practice. However, blend your pitcher’s in that session, showing them how to hit general locations - at ONE HALF GAME SPEED, is just as good as having a formal bullpen session. (wink wink.) So, have everyone show up out of uniform, not even a ball cap on, just sneakers, and have at it.
I had a guy who sustained a shoulder sprain. Under the Player’s Union agreement, he couldn’t be forced into any exercise program that put strain to his shoulder sprain. Ok… ok… no problem. I rented a row boat, got some fishing gear from my neighbor, and we both went out in the middle of good size lake in Upper State New York. I had a deep sea fishing pole with a four inch hook, no bait, and dropped my line. He, on the other hand, rowed me all around Lake George for two hours… taking a break now and then as I reeled in my line, had a bit to eat, then back at it again. Oh, by the way … my guy pitched the next day for the win. So, gotta think out of the box Skipper.,