The Guardians signed Armstrong to a one-year, $5.5 million contract with a mutual option for 2027 on Thursday, Jeff Passan of ESPN.com reports.

EDGE Analysis

The 35-year-old Armstrong had arguably the best season of his career in 2025 with the Rangers, putting up a 2.31 ERA, 0.81 WHIP and 74:20 K:BB over 74 innings. It's a return to the organization that drafted him and where he debuted back in 2015. Armstrong should be used in a setup role ahead of closer Cade Smith.

Armstrong recorded his ninth save of the season in Saturday's 3-2 win over the Mets, giving up a hit and striking out two over a scoreless two-thirds of an inning.

EDGE Analysis

Phil Maton got the final out of the eighth inning and the first out of the ninth before handing the ball off to Armstrong after a Juan Soto single. Armstrong did give up a drive into right field by Ronny Mauricio that nearly tied the game, but Dustin Harris was able to cut it off before it got into the corner and limit it to a single, and the right-hander then struck out Brandon Nimmo to end the threat. Armstrong has converted six straight save chances since taking over as the Rangers' primary closer in mid-August, and since the All-Star break he's delivered a dazzling 1.09 ERA, 0.69 WHIP and 26:5 K:BB in 24.2 innings.

Armstrong picked up the save Tuesday against Milwaukee, allowing one run on two hits and no walks across one inning. He didn't record a strikeout.

EDGE Analysis

Armstrong inherited a two-run lead but surrendered a solo home run to Jake Bauers. He stranded the game-tying run at first base, getting Christian Yelich to line out with Jackson Chourio on base to end the contest. Armstrong has allowed a run in two of his last five appearances, a streak that followed 11.2 consecutive scoreless innings. He's up to eight saves on the year.

Armstrong picked up the save Sunday against Houston, striking out one over 1.1 perfect innings.

EDGE Analysis

Armstrong has now pitched more than one inning in three of his last four saves. The 34-year-old hasn't yielded a hit or a walk in three consecutive outings, a streak that spans 3.2 innings. He owns a 2.40 ERA, seven saves and a 64:18 K:BB across 63.2 innings this season.

Armstrong struck out two in a perfect inning to earn the save in Monday's 7-5 extra-inning win over the Diamondbacks.

EDGE Analysis

Armstrong picked up his third save in his last six appearances when he shut the door in the 10th inning. His 11.2-inning scoreless streak was snapped Sunday versus the Athletics, but the right-hander has been one of the Rangers' steadiest bullpen arms lately. He's now at a 2.51 ERA, 0.84 WHIP and 63:18 K:BB while adding six saves, 10 holds and three blown saves over 61 innings.

Armstrong walked one over 1.2 scoreless and hitless innings to earn the save in Friday's 5-2 win over the Athletics.

EDGE Analysis

Armstrong's steady pitching in August looks to have vaulted him to the top of the Rangers' closing hierarchy. He's earned the team's last two saves, though chances haven't been plentiful in recent weeks. Phil Maton has blown three saves in his last five appearances, which has opened the door for Armstrong to get more closing opportunities. After Friday's outing, Armstrong is on an 11.2-inning scoreless streak with a 13:3 K:BB in that span. He's at a 2.43 ERA, 0.83 WHIP and 61:18 K:BB through 59.1 innings this season while adding five saves, 10 holds and three blown saves.

Armstrong earned his fourth save of the season during Sunday's 10-4 win over the Blue Jays, striking out one batter across 1.1 innings.

EDGE Analysis

The Rangers turned to Armstrong to get the final out in the eighth after Hoby Milner yielded a two-run homer to George Springer and Cole Winn walked two-straight batters. Armstrong helped Texas escape the frame after getting Alejandro Kirk out and stayed on to close things out in the ninth, ending the game by striking out Myles Straw. In 14 games since the All-Star break, Armstrong has allowed just one run on five hits and two walks while striking out 16 over 13.1 innings.

Armstrong earned a save against the Padres on Saturday by retiring the only batter he faced.

EDGE Analysis

Texas held a three-run lead going into the bottom of the ninth inning, and manager Bruce Bochy turned to top closer Robert Garcia to close things out. However, Garcia struggled, loading the bases with two outs. Bochy then turned to Armstrong, who got Xander Bogaerts to ground into a fielder's choice to end the game. The save was the third of the season for Armstrong, who notched his other two saves across a three-game span in mid-May. Garcia has been a bit shaky of late, but he's still the most likely reliever to get the call the next time a save situation arises.

Armstrong (2-2) took the loss against the Royals on Thursday, allowing two runs on one hit and one walk while striking out one batter in the first inning.

EDGE Analysis

With Nathan Eovaldi (triceps) on the injured list, the Rangers turned to Armstrong and the rest of the bullpen to fill the gap in the rotation. Armstrong took to the mound to start Thursday's game, but he gave up a two-run homer to Vinnie Pasquantino and was tagged with the loss as the Rangers were unable to muster up enough offense. Armstrong could serve as the opener next week against the Orioles at Camden Yards if Eovaldi is not cleared to return from the IL.

Armstrong will start Thursday's game against the Royals, Evan Grant of The Dallas Morning News reports.

EDGE Analysis

The Rangers are going to rely on their bullpen to get them through Thursday's series finale, and they will once again call upon Armstrong to start the game after also pitching the first three innings of Friday's win over the White Sox. The 34-year-old righty has been enjoying a nice bounce-back campaign this year, posting a 3.00 ERA and 1.00 WHIP through 30 innings.