Max Scherzer looks to continue his recent stretch of sublime dominance against the Dodgers on Friday night. (Jonathan Newton/The Washington Post)

The Washington Nationals will not have played a full baseball game in four days by the time they arrive at Nationals Park for their series opener against the Dodgers on Friday evening. Forecasts favor that streak extending to five days because record rainfall is expected in D.C. into Saturday morning. Whenever the series begins — and, just as uncertain, whenever it ends — this mid-May matchup will probably look a lot different than anyone expected when the season began.

DODGERS DOWN IN THE DUMPS

Before this season began, many experts thought the Dodgers would win the National League West. Still more thought they might win the National League pennant. After all, they came within a game of being World Series champions in 2017, and didn’t lose any of the key pieces that got them there this winter.

But many of those pieces have been hit by injuries this year. They began the season without third baseman Justin Turner, who has since returned. They lost shortstop Corey Seager to Tommy John surgery on his throwing arm, a huge blow to their lineup, and one that might just vault Nationals shortstop Trea Turner into the position of best all-around active shortstop in the National League. Ace Clayton Kershaw is on the disabled list with biceps tendinitis and not nearing a return. Closer Kenley Jansen has not looked as powerful or dominant as he used to.

To top it all off, they are simply not playing well, and have just one more win than the hapless Miami Marlins after beating them in Thursday’s series finale. To that extent, they will come to D.C. Friday with some degree of momentum. But by any other measurement, they are in free fall, with no stabilizing influence in sight.

WHEN IT RAINS, IT POURS

The Nationals got more frustrating injury news on Thursday’s day off, announcing that catcher Matt Wieters underwent surgery to repair his left hamstring — a procedure that will likely sideline him for some time. In the meantime, Pedro Severino will be the Nationals’ starting catcher, backed in the interim by longtime organizational favorite Spencer Kieboom. But the Nationals did not feel comfortable entering spring training with Wieters and Severino as their tag-team, as indicated by their pursuit of Miguel Montero. They likely will look elsewhere for help until Wieters returns.

None of the other injured Nationals — Daniel Murphy, Adam Eaton, etc. — will be back in time for this weekend’s series. Ryan Zimmerman will be eligible to come off the disabled list next week, so whether he does baseball activities this weekend will likely indicate his status.

In his absence, recently acquired first baseman Matt Reynolds will become increasingly important this weekend because the Nationals will face two left-handers, Rich Hill and Alex Wood. Though Manager Dave Martinez has been comfortable putting Matt Adams in the lineup against lefties, he would prefer not to, and now has a right-handed hitting alternative to play at first base — so long as he finds a capable right-handed hitting option to play left.

Moises Sierra has struggled lately, so Martinez may choose to move Howie Kendrick to left and play Wilmer Difo at second base against lefties. Reynolds, however, actually fares just slightly better against left-handed pitching (.788 career OPS) than he does right-handed pitching (.785 OPS). Zimmerman owns a .905 OPS against lefties in his career.

MOMENTUM KILLER OR STRENGTH BUILDER?

At the time of this week’s rainouts against the Yankees, the Nationals had won 13 of 15 and were deep in a charge up the National League East standings. One might wonder what effect this week’s rainouts will have — whether they might slow that momentum to a halt. But the good news is that no one in the Nationals’ lineup was on any kind of torrid hot streak at the time of the rainouts. Anthony Rendon was hitting well. Adams had cooled somewhat. Bryce Harper was driving the ball better by the end of last weekend’s series in Arizona, but was not in one of those crazy Harper streaks he sometimes falls into.

If anything, the off-days could give the Nationals’ pitching staff a chance to recharge. The big names at the back of the bullpen can rest — four days for Sammy Solis, Ryan Madson and Brandon Kintzler — and five for Sean Doolittle. Given that all of them are on pace for a record number of appearances this season, joking about their arms falling off now and then, the rest can only help.

PITCHING PROBABLES

Fri.: RHP Max Scherzer vs. RHP Ross Stripling

Sat.: RHP Tanner Roark vs. LHP Rich Hill

Sun.: RHP Stephen Strasburg vs. LHP Alex Wood

More on the Nationals:

As Matt Wieters has surgery on left hamstring, Nationals likely to hunt for catcher

Mailbag: Why do the Nats always lie about injuries? (Well, maybe not always.)

Thomas Boswell: The Nationals’ bullpen prayed for rain, and now it has a chance for much-needed reset

When it comes to Bryce Harper, doing enough means always doing more

Bryce Harper won’t play any games with N.Y. media