Performing the art of adding MLB prospects to your fantasy baseball roster mid-season can take a delicate touch. If you have a league with plenty of bench or N/A spots (as Yahoo! leagues now offer), it doesn’t hurt to stash away some future stars and sleepers off the waiver wire. You have plenty of other guys to stream from your bench to fill your positions. But in no-bench leagues, or leagues with just a few bench spots, carrying a minor league player and waiting for a call-up can do more harm than good. It is rarely worth it. Those “zero stats” guys can be a drain on your numbers and put you in a hole early in the season.

The prospect question most heard is "When will so-and-so be called up?” Without intimate knowledge of front-office decisions, that question is impossible to answer. We can only speculate based upon major league need, service time concerns and that player’s development.

The Astros gave George Springer the call-up on Wednesday after a month of speculation that they would wait until the Super Two deadline. The D-Backs announced that despite their desperate need for a starting pitcher, Archie Bradley will be staying in the minors for now, even though he’s better than their options at the major league level. This uncertainty requires fantasy owners to stay on top of team rumors, the transaction wire and the injury reports.

As usual, the most diligent fantasy owners will gain the biggest advantage over the course of the season. That said, this week I profile a few guys in the National League who may have a chance to help this season– or at least a few guys who are the “so-and-so’s” that fantasy owners are asking about.

Eye On The Minors - NL Prospect Updates

Oscar Taveras, OF - STL

Taveras would have been in the big leagues last season if not for a nagging ankle injury, so his long-awaited debut has been pushed back to 2014. The timetable for Taveras is “when he’s healthy and ready.” I know that Matt Adams and Allen Craig are fantasy darlings, but those guys will not block Taveras’ path to the majors. With Taveras, we have a potential NL batting champ with perhaps 30-HR pop who can sprinkle in a few steals as well. A fantasy beast and future first-round pick. He has hit to the tune of .289/.347/.489 in Double-A Memphis and has little more to prove in the minor leagues. By the end of the season, he could be the best hitter on the Cardinals.

Joc Pederson, OF - LAD

Poor Joc Pederson. Baseball America ranks him as the top prospect in the Dodgers' system, but he has nowhere to play at the big-league level. Pederson can hit. He is absolutely killing it at Triple-A Albuquerque with a .442/.564/.884 triple-slash line, five homers and four steals in his first twelve games. For many other teams, he’d be contributing at the big league level right now, but the Dodgers have enough trouble finding playing time with Andre Ethier, Yasiel Puig, Matt Kemp and Carl Crawford healthy and earning big contracts in their outfield. Pederson won’t get a chance this year unless the injury bug revisits L.A. or the Dodgers deal him away.

Tommy La Stella, 2B - ATL

Perhaps now is the wrong time to talk about a Braves second base prospect, with Dan Uggla coming off a two-homer game (including a grand slam) the other day. But as any fantasy owner knows, Uggla is prone to streaky hitting and monumental slumps. In the past few years alone, he has been benched for long stretches and was left off the NLDS playoff roster just last season. La Stella is the Braves best option on the farm to take over at second base if (when) Uggla struggles again. He was considered a candidate for the starting job out of Spring Training, but lost out to Uggla and was sent to Triple-A Gwinnett. La Stella doesn’t have power or great speed, but he can hit and get on base. I’ve seen generous comparisons to the Cardinals' Matt Carpenter. If he eventually gets the call, the young Brave could contribute in runs and batting average at a very shallow position.

Notes From the Minors

After finally finding his stroke following an 0-for-9 start, the Cubs’ Javier Baez was placed on the disabled list after rolling his ankle last Friday during fielding practice; he won’t be hitting, fielding or throwing for the next week or so, which will certainly delay his big-league debut... I mentioned the Pirates’ Gregory Polanco last week-- he currently leads the International League with a .485 average... Marlins’ lefty Andrew Heaney threw six shutout innings Tuesday night and may be ready for a call-up soon; the Marlins are certainly not shy about promoting young players.