BOSTON -- For Red Sox right-hander Matt Barnes, there was the slump that lasted for all of August that led to him getting a break from the closer's role.

Then there was the positive COVID-19 test that prevented Barnes from pitching from Aug. 30-Sept. 16.

Now, there is the battle of trying to shake off the long layoff in addition to the mechanical flaws he developed during that slump.

Barnes has pitched three times since being activated, and the first two outings were anything but smooth. In his first game back on Sept. 17, Barnes gave up a hit and a walk but did strike out two in a scoreless inning. Then came the unsettling performance on Wednesday against the Mets, when Barnes could get only one out while giving up a hit, a run and two walks.

In Friday's 8-3 loss to the Yankees, Barnes pitched a scoreless sixth inning, allowing just one hit and notching two strikeouts.

The veteran continues to study video and work out his mechanical issues with the coaching staff and he is keeping the faith that it will lead to something good. He knows that it has to be soon.

"It's definitely hard, but at the same time, you've got to find a way to do it," said Barnes. "Everyone [coming back from the COVID-19 injured list] is kind of dealing with the same thing. It's frustrating, but we're going to keep going. I'll get back there, but we've got to make it quick. We ain't got many games left."

In fact, the Red Sox have nine games left in the regular season, starting with Friday's opener of a three-game series against the Yankees.

At this point, Barnes isn't a high-leverage option for manager Alex Cora -- let alone the All-Star closer he was in the first half.

Barnes knows it is on him to change that.

"Barnesy, it seems like velocity is down," said Cora. "We'll keep working with him. Hopefully we can get him back on track, because we do believe that -- obviously -- when he's right, he's one of the best relievers in the big leagues. The velocity, the gap between the fastball and -- obviously -- his offspeed pitches, it's not as big as early in the season, but we'll keep working with him."

A dip in velocity is often related to mechanical issues, which Barnes acknowledges he currently has.

But there is another issue that must be fixed.

"At the end of the day, I think he has to get back to being aggressive -- being aggressive in the strike zone, getting ahead in the count," said Cora. "If he can do that, he'll be back. I cannot tell you if it's mental, but one thing for sure, attacking guys was a big part of what he was doing early in the season and he's not doing that right now."

However, Barnes doesn't think the issue is being any less aggressive in the strike zone. The issue in his mind is that he's trying to throw first-pitch strikes and the baseball is not cooperating.

"It's just a mechanical and a rhythm thing. I was really out of whack and really off timing-wise a couple of times," said Barnes. "First-pitch curveballs, I'm trying to just lay them in there for a strike. And they're kind of getting yanked. Fastballs are getting yanked, so it's just about getting the rhythm, the timing and the mechanics back in sync with each other and that will be good."

If Barnes needs an example of a recent Red Sox reliever who struggled mightily late in the season and then got back to being a significant weapon in October, he should look no further than Joe Kelly in 2018.

That September, there was some talk Kelly wouldn't even make the postseason roster. In 12 games over the final month of that season, Kelly had an 8.31 ERA.

During that postseason run, which ended with the Red Sox winning the World Series, Kelly had a 0.79 ERA in nine outings, walking none and striking out 13.

When that comparison was presented to Barnes, he said, "We'll see. We're going to keep working, we're going to keep moving forward. It will come back. This isn't going to last forever."