As spring training approaches, something is still missing from Red Sox

This isn’t about whether the Red Sox should sign Craig Kimbrel or why they didn’t pick up David Robertson or Andrew Miller when they had the chance.

This is about a simple math problem.

Kimbrel and Joe Kelly combined to pitch 128 innings in 2018, and they were largely very good ones outside of Kelly’s summer slump. Kelly has since signed with the Los Angeles Dodgers and Kimbrel remains a free agent.

The Red Sox need to replace those innings and probably a few more, given their plan to go easy on the starters in April coming off the World Series.

And that is where it doesn’t add up.

Ryan Brasier threw 33⅔ innings last season after being called up from the minors. It’s fair to think he could double that amount over a full season, but that still leaves approximately 95 innings to account for.

Dave Dombrowski and Alex Cora talk about Steven Wright coming back from injury and Padres castoff Colten Brewer being better than people think, and perhaps they will help.

But a team with championship aspirations can’t start the season hoping a 34-year-old knuckleballer who is still recovering from knee surgery can handle high-leverage spots.

Brewer is an undervalued asset the Sox analytics staff is high on. But he also was hit very hard in 11 major league games, and the last-place Padres felt they had better options for their 40-man roster.

The Sox also have Brian Johnson, Hector Velazquez, forever-rehabbing Tyler Thornburg, and assorted prospects. Over time, they could find seven or eight relievers they trust.

But there isn’t time. One of the tricks to avoid the dreaded World Series hangover is to start the season well. If the Sox are 15-15 after 30 games, it’ll be too easy to sit back and be happy about 2018.

We saw it happen in 2014 when they eased into mediocrity early on and never snapped out of it.

The Sox need to add one — or probably two — trustworthy relievers to avoid that.

It’s a reasonable decision not to pay Kimbrel, given the other players they’ll need to invest in over the next two years. His shaky second half and postseason were red flags.

So whether it’s Greg Holland, Ryan Madson, Tony Sipp, or some other established reliever willing to take a one-year deal and chase a ring, the Sox need to improve their options.

The Sox have a powerful lineup and a deep rotation. Why risk their potential to repeat with a rickety bullpen? Once that market starts to move, they need to move with it.

A few other thoughts and observations on the Sox:

■ For now, the Red Sox remain scheduled to visit the White House on Feb. 15. But if the government shutdown goes into next week, they could cancel or postpone the trip.

Ownership has made it clear it feels a celebration at the White House would be inappropriate with federal employees out of work or working without pay.

Cora appears unlikely to attend out of loyalty to his native Puerto Rico. Several Latino players have said they will not attend, are leaning against it, or haven’t decided.

Canceling or postponing the trip before spring training starts by citing logistics would make sense. That would enable the Sox to open camp focused on baseball and not on who is going to Washington.

■ Baseball America and Baseball Prospectus did not include any Red Sox on their Top 100 Prospects list.

That was expected. Strikeout-prone third baseman Bobby Dalbec is their top prospect, followed by infielder Michael Chavis, who was suspended last season for PED use.

But the Sox could still get help from their farm system this year.

Lefthander Darwinzon Hernandez, righthander Travis Lakins, righthander Mike Shawaryn, and lefthander Josh Taylor will be in major league spring training. All have a chance to contribute at some point.

Righthander Durbin Feltman, a third-round pick last June, should get to Double A Portland this year, and from there anything is possible.

■ “The Bill James Handbook” projects Mookie Betts for a .303/.384/.539 season with 29 home runs, 96 RBIs, and 27 steals. Also of note from the Handbook: Betts led the majors with a 1.092 OPS against fastballs last year. That helps to explain why he will hit second. Betts also made 13 outs of 390 or more feet.

■ The Red Sox were correct on 51.2 percent of their replay challenges last season, 15th in the majors.

■ As it stands, the Red Sox will have the same manager and coaches coming back. That has not happened since 2007-08, when Terry Francona had Luis Alicea (first base), John Farrell (pitching), DeMarlo Hale (third base), Dave Magadan (hitting), Brad Mills (bench), and Gary Tuck (bullpen) on his staff.

■ As for Farrell, the Cincinnati Reds recently retained him as a pitching consultant. But Farrell will not return to ESPN for a second year.

Farrell led the Sox to first-place finishes in 2016 and ’17. But 13 teams have changed managers since he was fired and none turned his way.

■ Betts will be in New York Saturday night to attend the New York baseball writers’ dinner and formally receive his American League MVP trophy. Dombrowski will present it.

David Price was named winner of the Babe Ruth Postseason MVP award but declined to attend.

■ The Professional Bowlers Association named Betts winner of its media award for the coverage he has generated for bowling over the last three years. Betts participated in the World Series of Bowling in 2015 and ’17.

■ The Cubs hired Craig Breslow as director of strategic initiatives for baseball operations. They also spoke to Mike Napoli about a coaching position but he elected to take some time off after retiring as a player.

A third member of the 2013 Red Sox, Jonny Gomes, is Arizona’s new outfield and base running coordinator.

The Sox would be wise to identify some more former players for roles in the organization. As Cora demonstrated last season, playing experience in Boston translates well to working with players.

■ Andrew Benintendi hit two home runs after the All-Star break last season and none in the playoffs, a stretch of 285 at-bats.

“In the second half, I became a better hitter,” Benintendi said last week. “I was going the other way, I was hitting more doubles. I’m not going to be that guy who hits 30, 35 [home runs] or whatever, so I’m fine with it. I’m a doubles guy.”

That’s not really true. Benintendi had a .897 OPS in the first half and .727 in the second half. He had a .384 slugging percentage after the break.

Benintendi has a sweet swing, but a Red Sox left fielder can’t be a singles hitter. How Benintendi balances hitting leadoff and generating more pop will be interesting to watch.

■ Trivia: Who was the last player to hit a home run off new Hall of Famer Mariano Rivera?

■ Some Hall of Fame thoughts:

With eight players voted in by the Baseball Writers’ Association of America the last two years, the ballot will open up over the next two years. The only newcomer with a realistic chance in that span is Derek Jeter.

The average ballot contained 8.01 names this year. Look for that number to drop, but more focus will be on borderline candidates.

The chief beneficiary should be Curt Schilling, who finished with 60.9 percent this time around. Schilling has three years remaining on the ballot to get to 75 percent.

Schilling was at 52.3 percent in 2016 before commenting on Twitter that a t-shirt calling for the lynching of journalists was “so much awesome.” He fell to 45 percent a year later and was at 51.2 percent in 2018.

Whether Schilling can recover more lost support remains to be seen.

As somebody who has voted for Schilling since he went on the ballot, I feel the focus should be on what he did on the field. But he did bring this on himself.

■ It’s hard to drum up much sympathy for Manny Machado, who remains a free agent.

Machado is a terrific player. But he’s also one who selfishly demanded to play shortstop last season despite being a much better third baseman. Then he demeaned the idea of hustling on the field, saying it was not his “cup of tea” and he didn’t plan to change.

He’s also a dirty player who has on several occasions spiked fielders for no good reason. If he didn’t end Dustin Pedroia’s career with an overly aggressive takeout slide in 2017, he significantly altered it.

Why would any owner want to invest a nine-figure contract on an unlikable player who has no interest in playing hard?

■ Trivia answer: It was Will Middlebrooks on Sept. 8, 2013, at Yankee Stadium, deep to right. The only other Sox players to connect off the unanimous Hall of Famer were: Manny Ramirez (2001), Shea Hillenbrand (2002), Kevin Millar (2003), Bill Mueller (2004), Jason Varitek (2005), David Ortiz (2006), and Jason Bay (2009).

Rivera played 19 years in the majors, appeared in 115 games against the Sox, and never allowed more than one home run against them in a single season. Amazing.

Peter Abraham can be reached at pabraham@globe.com. Follow him on Twitter @PeteAbe.