Friday always brings the mound aces to the fore for me. Luckily for you, if you have problems on the hill, it's that time of the week.Zach McAllister has made 11 starts this season and he's allowed more than three runs only twice (he's allowed four earned runs twice). In those 11 starts Zach has also never failed to last at least 5.2 innings in an outing. McAllister has impressed with a 8.17 K/9 mark which has helped him to another impressive mark, a 3.44 K/BB ratio. He hasn't exactly been missing a ton of bats, at least not in the solid contact column, given that his 22.3 percent line drive rate isn't exactly small (league average 19-20), and his 0.90 GB/FB ratio hints that his 0.92 HR/9 mark could inch up a bit. If it does, that solid ERA will end up looking like a league average mark. His consistency has been impressive and the K's are nice even if those ratios creep up over the final two months.Bronson Arroyo is well on his way to an 8th straight season of at least 29 starts and 199 innings as he's taken the pill 21 times while racking up 130.1 innings. He's posted some decent ratios with a 3.87 ERA and 1.24 WHIP, though he's just 7-6 with a mere 86 Ks on the year. Still, he's rolling right now. Winner of his last three decisions, Arroyo has thrown at least six innings in six of his last seven starts. Arroyo has also thrown five quality starts (more on that below) in those seven outings as he's dropped his ERA from 4.19 to that 3.87 mark. He's not elite, never will be, but if you need a place holder to give you some solid innings, sans the strikeouts, Arroyo could be your guy.Neftali Feliz, in case you missed it, had to undergo Tommy John surgery on Wednesday, a crushing blow to the Rangers who will now likely be without him for at least half of, if not all of, the 2013 season. What the hell is going on here? With all the advantages we have in the game today how on earth are pitchers blowing out their arms at an unprecedented rate? Thirty years ago guys threw 90 mph, didn't train in the offseason, and were 15 lbs overweight. Now guys throw 95, train year round, and have six percent body fat. Maybe the old couch potatoes were on to something? I'm just saying.Matt Harvey has been everything he was advertised to be in two starts as he's piled up 18 Ks in just 11.1 innings (14.29 K/9). However, he's also walked six batters and that lack of control will eventually catch up to you. As long as the matchup dictates it Harvey should be started in mixed leagues until further notice. The real worry with Harvey is workload. Adam Rubin of ESPN New Yorkreported Wednesday that the plan is to limit Harvey to 165-70 innings. Harvey is up to 121.1 innings so that still gives him 45 innings to work with which means he could be shut down late in September. Jeff Karstens has won his last four decisions for the Pirates and over his last five outings three times he's allowed one or zero runs. In total he's made 10 starts this season, around injury, and he's the owner of a 3.70 ERA and 1.20 WHIP. Given his work last season, 3.38 ERA and 1.20 WHIP, you might feel pretty comfortable running him out there every five games. Believe me I get it, but this is still a guy who doesn't profile well enough to support those ratios. I do like the fact that his K/9 rate is up, but can he really be expected to sustain a rate (6.75) that is nearly two batters above his career mark (4.94)? I can't expect that to continue (last year was his career best mark of 5.32). He keeps the walks down and doesn't beat himself, but this is a skill set I would trust only if he was also a ground ball hurler and he's just not. In truth, his GB/FB ratio of 1.00 for his career is actually slightly worse than the league average. Be careful here. Luis Mendoza continues to progress for the Royals. He may only have a 4.28 ERA and 1.44 WHIP as a starter this season, but five of his last six outings have been “quality” (three earned runs or less with six innings pitched or more). I'd still be leery of leaning too heavily on him though given the following numbers: 5.22 K/9, 1.41 K/BB. Still, he generates a ton of grounders, his GB/FB rate is impressive at 2.15, so at least he keeps the team in the game most of the time, provided all those batted balls find fielders gloves of course. Dan Straily will make his debut Friday as he will face the Blue Jays for the Athletics (Travis Blackley will be sent to the bullpen). A quick riser, he wasn't in the top-30 of Athletics prospects at the start of the year according to Baseball America, Straily has dominated minor leagues like nobodies business this year. The righty blew batters away in Double-A with 108 Ks in 85.1 innings before being promoted to Triple-A where batters haven’t fared much better (67 Ks in 53 innings). All told the youngster has made 22 starts this season leading to a 2.60 ERA, 0.97 WHIP, 11.39 K/9 and 4.73 K/BB. I don't know how you could ignore those numbers if you're in an AL-only league, and those of you in 15 team mixed leagues would be wise to jump on the bandwagon as well. I might hold off on that first start though as the Jays are a tough team to pitch against.Vance Worley has a 3.69 ERA and 1.39 WHIP on the year, and that's about as blah as you can get in this day and age of pitching. He's also just 6-6 on the year for the Phillies. More blah. His 7.51 K/9 mark is pretty much league average, as his his 3.06 BB/9 mark. Not exactly blah, but not exciting either. Now I am a fan of that 1.76 GB/FB ratio, but after a 1.10 mark his first two seasons, I don't know if I can trust that number to continue. Oh, and that line drive rate? Pretty scary actually at 24.3 percent. You might think a regression to the league average of 19-20 percent would be possible, and while it might be, it's hard to overlook the fact that he also posted a 23.5 percent mark last season in 131.2 innings. He's also been able to post a slightly elevated left on base percentage of about 76 percent since the start of last season, and that might hint at a wee bit of an increase in his ERA if it were to dip. He's solid as a back end starter but nothing more in standard mixed leagues. Ray Flowers can be heard daily on Sirius/XM Radio on The Fantasy Drive on Sirius 210 and XM 87 from 7-10 PM EDT, Monday through Friday. Ray's baseball analysis can be found at BaseballGuys.com and his minute to minute musings can be located at the BaseballGuys' Twitter account.