DETROIT -- Nicholas Castellanos doesn’t know how many games he has left in a Tigers uniform at Comerica Park. It could be two, if he’s dealt by the July 31 Trade Deadline. But that wasn’t on his mind as his 10th-inning drive sailed over the left-field fence for a 4-3 Tigers win.

“Why care if one day my hair’s going to turn gray if I can’t control it, you know,” Castellanos asked a crowd of reporters in response to trade rumors. “I don’t know if that analogy makes any sense, but it popped into my head. So no, whatever happens, I really don’t care.”

His hair isn’t anywhere near graying. It was, however, soaked, thanks to a water jug dumping during his postgame interview. After nearly six seasons as a Tiger, he had a walk-off home run to celebrate. And the Tigers, who had won one game at Comerica Park since June 8, had a home victory to appreciate.

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None of Castellanos’ 103 previous home runs had ended a game. Sunday’s drive salvaged one.

“It’s been frustrating around here, especially at home,” manager Ron Gardenhire said. “To finally come through and have a good ballgame here today, that’s important. That’s important that we start doing some of those things at home and get on a roll here.

“We needed it. We’ve been knocked down pretty good so far. That’s a good win.”

While Castellanos hasn’t drawn the same level of trade interest from clubs as starter Matthew Boyd or closer Shane Greene, it hasn’t been for lack of recent performance. Even before Sunday’s walk-off, he was putting up the best statistical month of his season. That has drawn the attention of the Cubs, whose interest was first reported by the Detroit News and later confirmed by MLB.com.

Though Castellanos’ defensive questions -- including -7 Defensive Runs Saved in right field -- have given pause to National League teams with no DH slot, his performance against left-handed pitching is an increasing draw as NL contenders ponder how to challenge a Dodgers pitching staff that features dominant lefty starters Clayton Kershaw and Hyun-Jin Ryu. It also created an advantageous matchup once the Blue Jays turned to lefty Tim Mayza for the bottom of the 10th inning in the series finale.

Castellanos jumped on Mayza’s first pitch and sent it deep to left for his 11th home run of the season. With that, he improved to .387 (24-for-62) with four home runs off left-handers this year. 

This home run, though, was different.

“I love these guys, this team,” Castellanos said. “We’ve been through a lot. The personalities on this team, we want to do well so bad, and they know that this is their opportunity. So the fact that everybody’s jumping on me, dumping stuff on me and we’re all smiling after a big win like that, that’s a good moment.”

It came an inning after Lourdes Gurriel Jr. hit a game-tying two-run homer in the ninth off All-Star closer and fellow trade candidate Shane Greene. It also came too late for Tyler Alexander, whose seven innings filled the Tigers’ need for starting pitching help but couldn’t fulfill his quest for his first big league win. What it means for Greene’s trade value will be seen over the next 10 days.

Alexander overcame a first-inning run to retire his final 14 batters, many of them testing the depths of Comerica Park. Nine of them came on flyouts, including four drives to the warning track or fence in a five-batter span between the fourth and fifth innings. Christin Stewart snagged Randal Grichuk’s leadoff drive in the fourth at the left-field fence. Castellanos corralled Justin Smoak’s drive just in front of the out-of-town scoreboard in right-center field.

Teoscar Hernandez’s drive to right-center leading off the fifth inning had a .560 expected batting average before JaCoby Jones tracked it down. But Jones topped it one batter later, crashing into the center-field wall to rob Brandon Drury of an extra-base hit on a drive with a .910 expected batting average.

“They hit some balls that were very fortunately caught,” Alexander said. “If the fences were 10 feet in, we’d be having a different conversation.”

Castellanos didn’t have much sympathy for Jays hitters, though he knows the feeling.

“How are we going to be compared to the rest of the people in the league for power numbers and OPS and slugging and all this stuff, and we’ve got a park out here that’s 420 feet straight across center field?” Castellanos, who also hit his MLB-leading 34th double Sunday, asked. “We get on second base or third base and they’re looking [at us] like, ‘Man, how do you guys do this?’ We play 81 games here. I don’t want to hear it about your two that you hit that are questionable.”

Jones’ leadoff home run in the bottom of the fifth built a 3-1 lead that carried to Greene in the ninth. But after Greene’s errant throw to first base put Eric Sogard on, Gurriel's 438-foot drive to left-center left no play for Jones, leaving Greene with his third blown save of the season.