Pedro Martinez and Vladimir Guerrero were only teammates for parts of two seasons in Montreal, but it was enough time to forge a relationship that stretched deep into familial territory.

By the time Guerrero was first called up to the Expos in 1996, his Dominican countryman was an established starting pitcher with a successful track record at the major-league level. The two roomed together and Guerrero was so grateful for the help of Martinez, who is four years older, that he made a pledge.

“I took him under my wing,” Martinez said on a recent Call to the Legend episode of ESPN’s Baseball Tonight podcast. “Vladdy promised me that whenever he had his first son, I was going to be the godfather.”

That godson, Vladimir Guerrero Jr., has grown to become the best prospect in baseball and a generational talent in the Toronto Blue Jays farm system. Martinez says he expects greatness from the 19-year-old.

“He’s got no ceiling,” Martinez told host Buster Olney. “He’s got a lot more [plate] discipline than his father. He was introduced to the things that he needed to do to hit a baseball at an early age, way before [Guerrero Sr.] probably thought about it. He’s got a lot more instruction than [his father] had. This is a special talent.”

Such talent has translated to impact results as Guerrero dominated double-A through 53 games with a .407/.457/.667 slash line to go along with 11 home runs and 20 walks against 21 strikeouts, before being placed on the disabled list with a knee injury earlier this month. Such production had many clamouring for the third baseman to be called up to the majors, but the injury, which could keep him out at least four weeks, will likely delay a promotion.

There is concern in some corners about Guerrero’s weight — he’s listed at 200 lbs., a number that’s sure to grow as his body develops. Martinez has noticed as much.

“He’s going to have to watch his weight because he’s a kid who is going to get really big,” he said. “But I’m pretty sure that with maturity and discipline, he’s gonna get to where he needs to be.”

Martinez, elected to the Baseball Hall of Fame in 2015, is set to welcome Guerrero Sr. to Cooperstown this summer when he is officially inducted. Both players left indelible marks on baseball in Montreal, a city that Martinez still holds dear. Asked about his thoughts on MLB possibly returning there with an expansion team, Martinez said he would support it “100 per cent.”

“Now you have revenue sharing, I don’t think that the team would struggle as bad as we did back in the those days,” Martinez said. “Everything would point to Montreal having a team and being able to keep it. I think Montreal is a great place to play — I was a witness, I lived it and I know that they will support a good team in Montreal. I know that for expansion teams, it normally takes a few years to actually get rolling, but Montreal will be very supportive.

“It’s a city that needs a team.”