Among the critical tasks of any Fantasy owner/general manager is the tracking of rotation changes throughout major league baseball.

The spate of injuries to pitchers has made that job particularly challenging this season. It seems a new hurler is removed and another inserted somewhere on a daily basis.

Knowing who to pick up and drop requires not only a knowledge of trends among low-end pitchers on big league rosters, but also those of premier prospects at the minor league levels. One must also be the first to strike when a pitcher goes down with a significant injury if his replacement is a worthy pick-up.

Here is a guide to what is currently transpiring among fifth starters on every American League team and their prospects for maintaining their spots. The special "Safe-O-Meter" ranks those prospects. 

Baltimore Orioles - Miguel Gonzalez   (Safe-o-Meter: 6)

Gonzalez has been slated to return to the starting rotation after Kevin Gausman was sent back to Triple-A in the wake of a failed start. But Gonzalez has been slipping in each of the last three seasons and must right himself to keep Gausman at bay and maintain his spot in the rotation. That spot is certainly more precarious than that of Bud Norris.

Boston Red Sox - Clay Buchholz (Safe-o-Meter: 7)

That Safe-o-Meter ranking could fall in a hurry, but the Red Sox are being patient with their 2013 phenom. He's 2-3 with a 6.44 ERA this year, but he has pitched quite well in two of his last three starts.

Chicago White Sox - Hector Noesi (Safe-o-Meter: 3)

Somebody is going to have to go when Chris Sale returns. At 0-3 with a 7.25 ERA, Noesi appears to be the most likely candidate, though Scott Carroll is another. One awful start on April 20, ironically against the White Sox, has skewed the numbers for Noesi, but he's likely not long for the starting rotation.

Cleveland Indians - Danny Salazar (Safe-o-Meter: 2)

Salazar better turn it around in a hurry to save his spot - he might not even get another chance. He has given up eight home runs in 40 2/3 innings and his ERA has risen to 5.53. He is throwing too many breaking balls in poor locations, his velocity is down, and Trevor Bauer (4-1, 2.15, 44 strikeouts in 46 innings) has been lights-out at Triple-A Columbus. 

Detroit Tigers - Robbie Ray (Safe-o-Meter: 2)

The return of Anibal Sanchez from the disabled list should knock Ray out of the rotation despite an encouraging stint in which he has yielded just one earned run in 11 1/3 innings covering two starts. He's only 22 and it's hard to imagine Brad Ausmus dumping Drew Smyly, who has also pitched well recently and has earned his spot.

Houston Astros - Collin McHugh (Safe-o-Meter: 9)

McHugh is listed as the fifth starter, but has outperformed Brad Peacock, who hasn't brought much more than a lot of strikeouts (39 in 38 1/3 innings) to the table. McHugh (2-1, 2.81) is also averaging more than a strikeout per inning, but has won two of three decisions with a 2.81 ERA. And anyone who can win games in Houston is going to stick around for a while.

Kansas City Royals  - Danny Duffy (Safe-o-Meter: 6)

The Royals will be hard-pressed to return Bruce Chen (1-2, 7.45) to the rotation upon his return from inury and take Duffy out. The former had struggled mightily to start the season and Duffy owns a 1.96 ERA with just nine hits and 17 strikeouts in 18 1/3 innings pitched.

Los Angeles Angels - Matt Shoemaker (Safe-o-Meter: 6)

Mike Scioscia is not about to yank Shoemaker out after a strong debut in which he gave up two earned runs in five innings, walked one and fanned three. Shoemaker replaced Hector Santiago, who was a mess as a starter, and he will get every opportunity to prove he belongs in the rotation. This Safe-o-Meter ranking will rise with every strong start.

Minnesota Twins - Samuel Deduno (Safe-o-Meter: 4)

By all rights, Deduno (0-2, 3.64) should not lose his gig to Mike Pelfrey (0-3, 7.99) when the latter returns from the disabled list. Deduno is coming off two solid starts. But they gave Pelfrey, who has begun his Triple-A rehab stint, a two-year, $11 million contract in the offseason and are unikely to give up on him at the quarter-pole of his first season. Deduno is probably the odd man out.

New York Yankees - Chase Whitley (Safe-o-Meter: 4)

Someone will have to go when C.C. Sabathia eventually returns, but Whitley opened some eyes with 4 2/3 shutout innings in his debut. And if continues to perform well, perhaps struggling Vidal Nuno will get the axe instead. Nuno has had just two decent outings and has given up 20 runs in 27 innings.

Oakland Athletics - Drew Pomeranz (Safe-o-Meter: 9)

This left-hander has fit in perfectly with the finest rotation in the American League. The converted reliever is 3-1 with a 1.44 ERA and has been lights-out in two starts. He has found the control and consistency that had eluded him throughout his professional career. He has walked just eight in 23 2/3 innings after issuing 19 free passes in 21 2/3 innings last season.

Seattle Mariners - Brad Maurer (Safe-o-Meter: 1)

Chris Young has outperformed Maurer, whose ERA of 6.20 will doom him upon the return of James Paxton to the rotation. Taijuan Walker is also on his way back, so Maurer has virtually no chance of sticking.

Tampa Bay Rays - Erik Bedard (Safe-o-Meter: 7)

Though Bedard has flirted with a renaiassance year before only to get hurt or fall apart, his flirtation is lasting longer this time around. He has compiled four straight excellent starts in which he has surrendered just two runs in 22 2/3 innings with 16 strikeouts. Struggling Cesar Ramos is more likely to be removed from the rotation when Alex Cobb returns.

Texas Rangers - Nick Martinez (Safe-o-Meter: 3)

It's hard to determine who the fifth starter is at the moment in this injury-riddled mess. Robbie Ross and Nick Martinez are lined up for starts this week, but the rotation is in a major state of flux. 

Toronto Blue Jays - J.A. Happ (Safe-o-Meter: 6)

The dispatching of Dustin McGowan to the bullpen has made Happ a safer bet to stay in the rotation, as has a decent stretch on the mound. Happ shut down Cleveland on Thursday and has performed well in two of his last three starts to forge a respectable 3.57 ERA. His walks - 12 in 17 innings - remain a concern, but he's shown encouraging signs of becoming more consistent.