The San Francisco Giants quest to follow up their wildly successful 2021 campaign has fallen short. They have already lost more games this season than they did all of last season, and as August comes to a close, their playoff hopes are hanging on by a thread.

The Giants are currently 5.5 games behind the San Diego Padres for the final National League wild card spot, and it's clear that if they intend on securing a playoff spot, they need to start their turnaround now. Otherwise, San Fran's playoff hopes will fade away over the next week or so.

San Francisco has a talented roster, but they clearly need reinforcements. Luckily, they will have some options for players to promote when rosters expand in September. Let's take a look at three prospects the Giants could promote in September to help them make a massive playoff push.

3 prospects the San Francisco Giants need to call up

3. David Villar

David Villar appeared to be on the verge of becoming a lost cause, but he has salvaged his career with a pair of solid seasons in 2021 and 2022. Villar has spent most of his 2022 campaign at Triple-A with the Sacramento River Cats, and he's been one of their best players all season long. San Fran doesn't have many major league ready prospects, but at 25 years old, it's clear that Villar is one of them.

Villar has found his power stroke with the River Cats this season (.281 BA, 26 HR, 77 RBI, 1.041 OPS) and has shown his upside as a hitter. If Villar could replicate those stats in the majors, he would be one of the better hitters in the game, but in his limited action in the majors this season, he's hitting just .175.

The problem is that Villar is running out of time to develop. He's already 25 years old, and needs to establish himself in the majors. He's very likely to get promoted in September, and he could be a solid bench option for the Giants moving forward. But given their lineups struggles this season, it makes sense to give Villar a longer look in September to see if he has what it takes to stick in the majors.

2. Gregory Santos

Gregory Santos has potential that he hasn't been able to reach in the minors so far. A transition to the bullpen was made in an attempt to help him, but it hasn't proven to do much to help him. But he's one of the more major-league ready prospects the Giants have, and they could use another arm in the bullpen, making Santos a relevant call up option.

Santos has been a middle reliever for the River Cats at Triple-A this season, and he hasn't been very effective for most of the season. His numbers (1-2, 4.91 ERA, 34 K, 1.49 WHIP) raise the question of why he would be promoted in the first place. Santos has clearly struggled, but with a bit of work, he can develop into a solid reliever for the Giants.

At this point, San Francisco has nothing to lose. Giving Santos a shot doesn't really hurt them, as he would be used in low leverage situations out of the bullpen to ease him into the majors. If he pans out this season, great, but if not, he still has time to develop, which makes promoting Santos a low-risk/high-reward move for the Giants.

1. Kyle Harrison

Kyle Harrison is the 22nd overall prospect in the MLB right now, and for good reason. He's flummoxed hitters no matter which level he's pitched at early in his career, and based on how good he's been in Double-A this season, the Giants may want to give him a shot to prove himself in the minors while their playoff hopes are still alive.

Harrison quickly earned himself a promotion from High-A to Double-A this season after he had a 1.55 ERA in his seven starts at High-A. Harrison's ERA hasn't been as glaorous as that at Double-A, but his numbers are still solid (4-2, 2.56 ERA, 94 K, 1.11 WHIP) and should warrant a promotion to the majors in September.

Harrison is going to be a starter throughout his career, but the Giants could use him in either their rotation or bullpen if he were to get called up. Realistically speaking, the front of San Fran's bullpen has been a mess for most of the season, and they could use a consistent arm in Harrison. Harrison could be used in low leverage situations, while also making a spot start from time to time. Getting him some exposure in the majors wouldn't hurt, and given how good he's been this season, he may be able to make an immediate impact.