Description: Orioles third baseman Manny Machado was scratched from Tuesday's lineup with lower back tightness, according to Brittany Ghiroli of mlb.com.
Insight: Machado has batted .333 with seven doubles, six homers, 12 RBI, 11 runs and a .931 OPS over his last 29 games after hitting .218 with a .595 OPS in his first 37. He has 10 homers in 258 at-bats after hitting just 14 in 667 at-bats last season. Consider him day-to-day.
Description: Third baseman Chase Headley has been traded to the New York Yankees.
Insight: Headley hasn't ever reached the levels he posted in 2012, but he'll be an upgrade at 3B for the Yankees. The change in venue from Petco Park to Yankees Stadium will should help Headley's numbers. He's not in Tuesday's starting lineup.
Description: Third baseman Yangervis Solarte has been traded to the San Diego Padres.
Insight: Solarte went 40-for-119 (.336) with 10 doubles, four homers, 23 RBI, 17 runs and a 16/17 K/BB in his first 34 games this season, but he went 23-for-123 (.187) with two homers and seven RBI since then. In pitcher-friendly Petco Park, Solarte will have no fantasy value.
Description: Astros third baseman Matt Dominguez could be a good low-cost fantasy option Sunday against the White Sox.
Insight: Dominguez has a .295 average and an .800 OPS against lefties this season, compared to a .209 average and a .580 OPS against righties. He's also gone 3-for-5 with two homers against White Sox left-hander John Danks.
Description: Red Sox third baseman Xander Bogaerts went 1-for-3 with a homer, two RBI, a walk and two runs scored Friday against the Royals.
Insight: In his last 29 games of the first half, Bogaerts batted .103 (11-for-107) with one extra-base hit, five RBI and seven runs. Before that stretch he had a .299 average, five home runs and an .840 OPS on the season.
Description: Reds third baseman Todd Frazier went 1-for-5 Sunday, but his lone hit was a home run.
Insight: Frazier has a big chance to introduce himself to casual baseball fans during the All-Star break, as he'll participate in the Home Run Derby and the All-Star Game. Fantasy owners are already very familiar with him, as he's batted .290 with 19 homers, 53 RBI, 57 runs, 14 steals and an .852 OPS this season.
Description: Pittsburgh third baseman Pedro Alvarez is 5-for-28 lifetime against Reds starter Johnny Cueto.
Insight: Alvarez is hitting just .238 with 15 home runs, 47 RBI and a .741 OPS. At the All-Star break last year, he was hitting .250 with an .827 OPS and already had 24 homers and 62 RBI. He'll face Cueto Sunday in Pittsburgh's last game before the break.
Description: Reds third baseman Todd Frazier has gone 5-for-14 (.357) with a double, two homers and three walks against Pirates starter Francisco Liriano.
Insight: Frazier has been the Reds' best hitter this season, batting .291 with 18 homers, 51 RBI, 56 runs, 14 steals and an .850 OPS. He'll put his power on display Tuesday in the Home Run Derby, but not before getting a crack at Liriano Sunday.
Description: Brewers third baseman Aramis Ramirez has a favorable matchup with Cardinals ace Adam Wainwright.
Insight: Wainwright is one of the top-two pitchers in the National League, but Ramirez is a career .404 hitter (19-for-47) with a pair of home runs in their matchups. Despite a trip to the injured list, Ramirez is putting together another solid season batting .285 with 11 HR and 42 RBI in 68 games.
Description: Reds third baseman Todd Frazier is 5-for-12 (.417) with one home run against Pittsburgh starter Jeff Locke.
Insight: Frazier carried the Reds offense early on this season and has been playing at an All-Star level, batting .289 with 17 HR, 48 RBI, 13 SB and an .842 OPS. Cincinnati will need him to carry them a bit further with all the injuries they have suffered recently (Joey Votto, Brandon Phillips, Billy Hamilton).
Description: Athletics third baseman Josh Donaldson slammed his 20th home run of the season Thursday afternoon.
Insight: Donaldson has struggled after a good start, but the home runs have never slowed. He'll easily top last year's total of 24, but he'll be hard-pressed to match last season's .301 batting average or .883 OPS.
Description: Mets third baseman David Wright is a career .423 hitter (11-for-26) against Braves starter Aaron Harang.
Insight: Wright had a bruised rotator cuff and missed seven consecutive games. He's been a solid RBI guy this season (43), but seven home runs and four steals are below expectations for the Mets star third baseman. Perhaps this matchup will help.
Description: Chicago third baseman Conor Gillaspie went 2-for-4 with a double and a solo homer Wednesday at Boston.
Insight: Gillaspie has finally started to hit for some pop after failing to hit one out of the park in his first 59 games. He's hit three in his last six games and is now batting .320 with 21 doubles, three triples, 33 RBI, 32 runs and an .835 OPS in 247 at-bats.
Description: Orioles third baseman Manny Machado banged out three hits, including a solo homer Wednesday against the Nationals.
Insight: Tuesday's rainout did nothing to cool off Machado's scorching bat. He's gone 12-for-21 (.571) with two doubles and two homers in his last four games and 22-for-51 with three doubles and five home runs in his last 12.
Description: Twins third base prospect Miguel Sano (elbow) will not play in the Arizona Fall League but could get some action in winter ball, according to Rhett Bollinger of mlb.com.
Insight: Sano underwent Tommy John surgery in March. The 21-year-old third baseman already has 90 home runs in 1,375 minor league at-bats. Baseball America ranked Sano as the No. 6 prospect in baseball prior to this season.
Description: Reds third baseman Todd Frazier is 6-for-17 (.353) with two home runs against Cubs starter Travis Wood.
Insight: Frazier carried the Reds offense early on this season and has been playing at an All-Star level, batting .293 with 17 HR, 48 RBI, 13 SB and an .859 OPS. He has four multi-hit games in the last five contests.