Guerrero (hamstring) is not in the lineup for Tuesday's game against the Pirates.

The first baseman was headed for an MRI after exiting Monday's game due to left hamstring tightness, and he'll be held out of the starting nine for at least one contest. Guerrero should continue to be considered day-to-day until the MRI results are announced.

Tellez started at first base and went 1-for-4 with an RBI in Monday's 4-3 loss to Kansas City.

Tellez got the call at first base in the Rangers' first game after the team placed Jake Burger (wrist) on the 10-day injured list. Tellez could serve as the strong side of platoon at first base while Josh Smith covers right field in the absence of Adolis Garcia (ankle). Joc Pederson, who was the designated hitter Monday, is also a left-handed bat that could play first base against righties.

Lowe entered Monday's game as a pinch hitter, walked and scored a run in a 6-3 loss to the Orioles.

Lowe pinch hit in the bottom of the ninth inning and was not needed for the field. He was officially added to the roster Monday and wasn't in the starting lineup against a left-hander. Lowe could enter the starting nine Tuesday against Baltimore right-hander Tomoyuki Sugano.

Guerrero (hamstring) will undergo an MRI on Monday night, Keegan Matheson of MLB.com reports.

This should help the club determine next steps for the slugger, who exited Monday's game early with left hamstring tightness. Matheson notes that Guerrero's removal may have been precautionary, though the team won't know for sure until viewing his scans.

Guerrero left Monday's game against the Pirates due to left hamstring tightness.

The severity of Guerrero's injury is not yet clear. He'll presumably be sent for additional scans to determine whether he can take the field Tuesday. Ty France would be in line for chances at first base if Guerrero is forced to miss more time.

Guerrero (undisclosed) was removed from Monday's contest against the Pirates in the fifth inning, Mitch Bannon of The Athletic reports.

Guerrero was replaced at the plate by Ty France with two outs in the top of the fifth inning. It's unclear why Guerrero exited the contest, but more information on his status will likely come in the near future. The first baseman will end his day having gone 0-for-2 from the plate with an RBI and a strikeout.

Lowe signed a one-year contract with the Red Sox on Monday but won't be included in the lineup for the team's series opener versus the Orioles.

The switch-hitting Abraham Toro will draw the start at first base while the Red Sox face off against lefty Trevor Rogers in the series opener, but the left-handed-hitting Lowe is likely to occupy the strong side of a platoon at the position with Toro or the right-handed-hitting Romy Gonzalez. Lowe was in the midst of a disappointing season with Washington before he was released over the weekend, but he had performed at a slightly above league-average level against right-handed pitching, slashing .235/.312/.412 with a 104 wRC+ over 337 plate appearances.

Mayo is out of the lineup for Monday's game against the Red Sox.

Mayo will give way to Ryan Mountcastle at first base in the series opener in Boston, after Mayo had started in each of the Orioles' previous six contests. After a productive stretch at the plate coming out of the All-Star break, Mayo has taken a step back offensively to begin August; he's slashing just .160/.222/.320 with four extra-base hits through 15 games this month. With top prospect Samuel Basallo getting called up from Triple-A Norfolk on Sunday and likely to see a near-everyday role while bouncing between designated hitter, catcher and first base, Mayo may need to pick up the pace to hold off both Basallo and Mountcastle for at-bats.

The Rangers placed Burger on the 10-day injured list Monday with a left wrist sprain, Evan Grant of The Dallas Morning News reports.

Burger exited Sunday's game against the Royals due to wrist discomfort, and a follow-up MRI revealed a sprain. The severity of the sprain isn't known, so it's unclear how much time Burger might miss. Rowdy Tellez should continue to see the bulk of the starts at first base against right-handed pitching, with Ezequiel Duran stepping in versus southpaws.

Lowe and the Red Sox agreed to a one-year contract Sunday, Jeff Passan of ESPN.com reports.

Lowe was granted his release from the Nationals on Saturday and has quicly found a new home in Boston. The 30-year-old had slashed .216/.292/.373 slash line with 16 home runs and one stolen base over 119 contests with Washington, where he had been handling an everyday role at first base. The Red Sox have struggled to find a consistent option at first base this season, and the left-handed-hitting Lowe could occupy the strong side of a platoon at the position with the right-handed-hitting Romy Gonzalez. Lowe owns a .732 OPS over 337 plate appearances versus right-handed pitching this season.