That similarity rests in a common goal -- one shared by a number of pitchers, both young and old -- to prove that they are recovered from recent injuries and ready to meet even the highest of expectations this year.
The early returns on Strasburg and Santana, including Wednesday's showdown, certainly provide an optimistic outlook. Strasburg tossed six scoreless innings, lowering his ERA to 0.69 through two starts, and the 23-year-old surpassed the 100-pitch mark for the first time in his big league career.
"I'm going to handle him just like he is perfectly healthy," Nats manager Davey Johnson said of Strasburg, who also made five September starts last season. "There was plenty left in the tank there."
As for Santana, he followed up five shutout frames in his season debut with another solid five-plus-inning outing Wednesday. Allowing one run on five hits, Santana fell just one pitch shy of the 100-pitch plateau.
"It was a tough challenge out there, but it was good to see that I was able to go beyond 80 pitches and able to go out there without any problems," Santana said after the Mets' 4-0 loss. "Unfortunately, we didn't win, but as far as how I'm doing, I think I'm making progress."
For pitchers returning from extended absences, it's that "progress" more so than stats alone that's often used to measure those first few starts. So while everyone would ideally like to post Strasburg-type or even Santana-type numbers right out of the gate, the reality is that doesn't always happen.
Just ask the Marlins' Josh Johnson or the Cardinals' Adam Wainwright.
Johnson, shelved with right shoulder inflammation after just nine starts last season, followed up a rocky debut with one of the worst outings of his career Wednesday night against the Phillies. Therein lies that altered definition of success, though. While it certainly was a treacherous start numbers-wise, it wasn't so bad confidence-wise.
Sure, Johnson has allowed double-digit hit totals in each of his first two starts after doing it only once in his career prior, and he's allowed nearly one run per inning so far (nine runs in 9 2/3 innings). An optimist, however, would point out that 10 of the 11 hits allowed on Wednesday were singles and that five of the six runs conceded by Johnson came in an inning that included a questionable safe call at second base -- a base hit that ricocheted off Johnson into left field -- and a fielding error.
"I felt really, really good," he said after the 7-1 loss. "In Spring Training, everything felt good. I kind of took a step back the first start, but this start was good, just a bad result. I made some good pitches and just didn't come out on the right side."
As for Johnson's fastball hovering around the 92-93-mph range -- he was throwing around 96-97 before the injury -- it's common even for a healthy power pitcher's velocity to be the last thing to come around for him after Spring Training.
"Even though you have Spring Training and all that, pitching in a big league game when it counts is different," said bench coach Joey Cora, who is filling in for Ozzie Guillen during his five-game suspension. "It's going to take a little bit of time for him to be the JJ that everybody knows. I know JJ is going to get better. I know he's going to get better, because he's a whole lot better than that. I expect his next outing to be really, really good."
The fact is, at this point in the season, the sample size is much too small to properly assess a pitcher's progress. For instance, going strictly off the numbers from Wainwright's first start since having Tommy John surgery last February (three runs on four hits in 5 2/3 innings) wouldn't necessarily lead you to the conclusion drawn by teammate Lance Berkman.
"If he pitches like that," Berkman said after the 6-0 loss to the Brewers, "he's going to win 20 games."
There are plenty of guys to keep an eye on, ranging from Strasburg and Johnson to veterans like the Rockies' Jamie Moyer and the Giants' Barry Zito. A win for Moyer (Tommy John surgery in December 2010) would make him the oldest pitcher to record a Major League victory. Zito, meanwhile, already recorded his first shutout since '03 in his season debut after starting a career-low nine games last year due to various injuries.
Keep in mind that each pitcher will have a different barometer of success. While a pitcher like Strasburg will look to establish himself as a legitimate staff ace, veterans like Santana aim to make sure opposing hitters still don't enjoy stepping into the batter's box against them -- even if that hitter is a fellow pitcher on the road to recovery.
"He made me look stupid with that changeup, that's for sure," Strasburg said after facing the southpaw. "It's impressive -- not only what he did [Wednesday], but just to be able to come back from all those injuries and stuff and still have the command and everything."