Question is, how much will King Felix help?

After spending nearly two months on the shelf due to inflammation in his right shoulder (the longest forced absence of his 13-year career), Felix Hernandez Friday at Safeco Field  rejoins the Mariners (38-37), above .500 for the first time this season. After a 9-6 win over Detoit Thursday extended a winning streak to five games, Seattle faces the team with MLB’s best record, the 50-24 Houston Astros.

While King’s Court denizens will almost certainly expect Hernandez to provide a significant boost to a pitching staff that ranks last in the American League in quality starts, 14^th in earned runs allowed, 12^th in runs allowed, 12^th in opponent batting average and 11^th in ERA, it’s hardly a given that Seattle’s one-time ace will be able to do any such thing.

Not that he’ll be a liability, but how much can he add?

Before he went on the DL April 25, Hernandez had a 2-2 record with a 4.73 ERA (Mariners were 2-3 in his starts). He had one vintage outing, against Texas April 14, allowing one earned run with no walks in 7.1 innings.

But uncharacteristic of Hernandez in his heyday, in a no-decision against the Angels April 8 — five days after losing to the Astros 3-0 in the season opener — he allowed 10 hits in a 5-4 Seattle loss. On April 19, he yielded 12 in a 10-5 win over Miami.

The 31-year-old Hernandez will return to the Mariners having thrown 2,442 career innings, a total exceeded by only three active pitchers, 36-year-old C.C. Sabathia (3,243), 44-year-old Bartolo Colon (3,231) and 38-year-old John Lackey (2,751). Sabathia and Colon are on the DL.

In addition to Hernandez and that antique trio, nine others have crossed the 2,000-inning threshold. This is where the 13 rank this year in WAR (wins above replacement), which represents the number of wins a player hypothetically has added to his team above what a replacement player would have added:

Of those listed, only Santana, Greinke, Sabathia and perhaps Verlander, who had a perfect game for six innings against the Mariners Wednesday night, are currently the most effective pitchers on their respective teams. But nearly every one of the 13 are being paid ace money, including Hernandez.

This is the scale Baseball Reference uses to measure WAR: 8+= MVP quality; 5+= All-Star quality; 2+= starter; 0-2 = reserve. Based on how the stat works (it charts success over time), an All-Star pitcher should have a WAR of 2.8 or higher at this point in the season. Only Santana qualifies.

So from Greinke on down, all of the 2,000-inning pitchers are largely earning a fortune while delivering average to below-average results.

Hernandez might have a WAR higher than 0.2 if the hadn’t missed nearly two months. For comparison purposes, 27-year-old Sam Gaviglio, who came to Seattle in November, 2014, in a trade from the St. Louis Cardinals, has logged only 13 more innings than Hernandez this season, but has a WAR of 0.4.

Then again, Hernandez’s WAR might not be substantially better if he hadn’t gone on the DL. Last year, over the span of 25 starts, his full-season WAR was 1.6 (11-8, 3.82), making him a reserve, according to the Baseball Reference definition.

Also according to Baseball Reference, Hernandez hasn’t been an “All-Star quality” pitcher since 2014, when he went 15-6, led the AL in ERA at 2.14 and finished with a 6.8 WAR.

Chew on this: Greinke led MLB in WAR two years ago at 9.3. After crossing 2,000 innings midway through the 2015 season, his WAR number plummeted to 2.3 in 2016. This year, he’s improved a couple of ticks to 2.5 while earning $34 million, stark evidence of the high risk of long-term extensions given to pitchers already in their primes.

Since Hernandez went on the disabled list, Ariel Miranda (1.5 WAR), James Paxton (1.2), Gaviglio (0.4), Christian Bergman (-0.1) and Yovani Gallardo (-0.7) have been Seattle’s most frequent starters (Bergman was just optioned to Tacoma). Adding up their WAR numbers gets 2.4.

For that matter, add up the WAR numbers for every pitcher who has started a game for Seattle this season. It’s 2.2 (spot starters such as Robert Whalen, Chris Heston and Ryan Weber all had negative WARs). When Hernandez won the Cy Young in 2010, his WAR was 7.1.

In the era of divisional play (since 1969), more than 250 pitchers have thrown 2,400 or more innings. With only a few exceptions (Nolan Ryan and Randy Johnson, for two), the WAR numbers for those pitchers declined steadily after 2,400 innings had been crossed.

The majority of pitchers ended like Pedro Martinez. The year he hit 2,400 innings (2005), his WAR was 6.9. Over the next four years, which spanned 313 innings, his WAR never topped 1.0 in any season. That looks a lot like the Hernandez trend line.

However, Hernandez might surprise. If he is to become an exception, no better time to start than Friday with the Astros in town and the Mariners offense (34 runs in the five wins) on a roll.