At some point soon, the Boston Red Sox figure to clinch the 2017 AL East division title. Any combination of Red Sox wins or Yankees losses totaling three the rest of the season will clinch the division for Boston. It would be the first time Boston has won division titles in back-to-back seasons. Ever. The last time the Red Sox finished in first place in consecutive seasons was 1915-16, when the American League was just one league. 

The Red Sox have lost their last two games, both to the Blue Jays, and while back-to-back losses is usually nothing to fret about, those two games continued a troubling trend for Boston. Their starting pitching is becoming worrisome in the final week of the season. In Monday's loss (TOR 6, BOS 4), Drew Pomeranz got knocked around for five runs on seven hits and one walk in two innings. He didn't strike out a single batter.

Then, in Tuesday's loss (TOR 9, BOS 4), Chris Sale surrendered four home runs and five runs total in five innings. He did strike out eight, though eight hits and two walks in five innings is decidedly un-Sale-like. Tuesday night was only the second time in Sale's career -- and the first time since way back in 2013 -- that he allowed four home runs in a single game. Watching your ace throw batting practice is never fun.

Monday's game and Tuesday's game were troubling for different reasons. Both Pomeranz and Sale continued recent trends that at best should raise an eyebrow and at worst are cause for panic.

Pomeranz's velocity is down

All things considered, throwing 167 2/3 innings with a 3.38 ERA (134 ERA+) is really good, especially when Fenway Park is your home ballpark and you make plenty of starts in all those other hitter friendly AL East parks as well. That's what Pomeranz has done this season.

Lately though, Pomeranz's velocity has been trending down, and when a pitcher loses velocity, it's difficult to expect him to maintain his performance to date. Here, via Brooks Baseball, is Pomeranz's average fastball velocity start-by-start this season:

Drew Pomeranz's fastball velocity is way down in September. Brooks Baseball

Pomeranz's average fastball velocity from April through August: 92.0 mph. Pomeranz's average fastball velocity in September: 90.7. In his last two starts, his heater has averaged 89.4 mph. Hmmm. That's not good.

Now, just about every pitcher who has thrown 160-something innings is losing some velocity at this point of the season. Fatigue and wear-and-tear begin to set in. Pomeranz is a bit of a special case though because his velocity drop is so sudden and steep, and also because he has an injury history. Remember, when the Red Sox acquired him from the Padres last year, San Diego did not disclose a pre-existing elbow issue. Pomeranz has been received regular treatment on the elbow for quite a while now.

Sale is suddenly home run prone

Tuesday night was the second four-homer game of Sale's career. He has only five career starts with three home runs allowed, and one of those came earlier this month. The Yankees tagged him for three homers in 4 1/3 innings on September 3. So two of Sale's seven career starts with at least homers allowed have come this month. Here is Sale's home run rate this year, via FanGraphs:

Chris Sale has become more and more home run prone late in the season. FanGraphs

It is 2017, and pretty much every pitcher is home run prone these days, so perhaps we're focusing on this a little too much. It is at least a little unsettling Sale's home run rate is definitely trending upward late in the season. 

It's worth noting Sale does have a little bit of a history of wearing down late in the season, and given the upcoming schedule, he figures to get a nice long break before the postseason. He will be available to start Game 162 if the Red Sox need to win that game, otherwise they can shut him down for a bit and have him ready to go for Game 1 of the ALDS.

Sale and Pomeranz have been Boston's two best starters all season, and now both are, if nothing else, showing troubling trends late in September. Pomeranz is continuing to lose velocity and Sale is having trouble keeping the ball in the park. Rick Porcello, the reigning AL Cy Young winner, leads the league in losses and hits allowed, and has a 4.55 ERA (99 ERA+) in 197 2/3 innings. Doug Fister and Eduardo Rodriguez have had their moments this year, though neither has been consistent.

As odd at is sounds, the Red Sox are a below-average offensive team this year, hitting a combined .258/.330/.407 (92 OPS+) in 2017. They are dead last in the AL with 163 home runs, amazingly. This Red Sox team needs high-end pitching to win, and for much of the season, Sale and Pomeranz provided that. Both have now hit a rough patch late in the season, and Pomeranz's velocity and Sale's home runs give the club some reasons to worry heading into the postseason.