The Washington Nationals take on the Seattle Mariners. Check out our MLB odds series for our Nationals Mariners prediction and pick.

Erick Fedde goes to the mound for the Nationals, while Robbie Ray will start for the Mariners.

Erick Fedde has been injured and will be making his first start since July 24, one month ago. That is the first thing you need to know about him. He had a 3.55 ERA on May 29. The fact that his ERA currently stands at 4.95 might lead you to think that he has been consistently poor since then, but it's not necessarily the case. Fedde got crushed by the Mets on May 30, giving up six runs in 1 1/3 innings, to send his ERA to 4.60. Fedde hasn't been particularly good, but his ERA has remained relatively steady over the past two and a half months. No regression, no improvement, just maintaining course.

Fedde will occasionally pitch six scoreless innings, doing so in one out of every seven or eight starts, so he'll show what he is capable of at times. Generally and broadly viewed, however, he is an ordinary pitcher, exactly what is ERA would indicate. He spent June and July pitching roughly five innings per start and giving up two to three runs, which is what a five-run-ERA pitcher does.  It will be interesting to see if he is noticeably sharper after his one-month layoff.

Robbie Ray had a terrible April and May. His ERA on June 6 was 4.97. He bore very little resemblance to the man who won the Cy Young last year with the Toronto Blue Jays. The one glimmer of hope for Ray, even when his results were terrible, was that he was pitching three clean innings and then running into a big inning. He did pitch well for short segments, but he couldn't stay out of the big inning. That reality was frustrating, but it did offer the hope that if Ray could avoid big innings, he would straighten things out. That's what he did in June and July.

In a six-start sequence from June 12 through July 9, Ray pitched 39 2/3 innings and allowed four runs. He did not allow more than one run in any of those six starts. He regressed just after the All-Star break when the Houston Astros pounded him twice, but the Astros are a great team. Ray has pitched well against subsequent opponents over the past three and a half weeks. After those two ugly starts in late July against Houston, Ray has pitched to a 2.33 ERA in three August starts, throwing 19 1/3 innings and allowing just five runs. He has his house in order.

Courtesy of FanDuel, here are the Nationals-Mariners MLB odds.

MLB Odds: Nationals-Mariners Odds

Washington Nationals: +1.5 (+108)

Seattle Mariners: -1.5 (-130)

Over: 7.5 (+100)

Under: 7.5 (-122)

Why The Nationals Could Cover the Spread

Erick Fedde, if fully recovered from his injury, could pitch a really good game. He will have a strong outing every now and then — not a majority of the time, but one time is all he needs to cover the spread for anyone who bets on Washington. That point aside, the Mariners just lost two straight games to the lowly Oakland Athletics. This is not a team playing particularly well, and the Nationals just split a four-game series with the San Diego Padres on the road. Washington has a terrible record, but the Nats are playing hard. They're not a pushover, and their pitching has been really good, holding the Padres to a grand total of eight runs in four recent games in San Diego. This pitching staff can contain the Mariners.

Why The Mariners Could Cover the Spread

After the two-game losing streak in Oakland, the Mariners are going to be mad. They have an in-form version of Robbie Ray, who should shut down the Nats' bats and enable the Mariners to comfortably cover the spread as long as they can create four or five runs.

Final Nationals-Mariners Prediction & Pick

Erick Fedde might pitch well. Robbie Ray WILL pitch well. That's the essential difference here. Take the Mariners.

Final Nationals-Mariners Prediction & Pick: Mariners -1.5