The sight of Mauro Diaz making his way toward the home bench before last Saturday night’s quizzical match between FC Dallas and FC Toronto must have represented a welcome sight of relief for those of a Dallas persuasion. In a different way, the Toronto ranks too might well have taken some solace from the fact he was safely ensconced in the Toyota Stadium technical area.

For the briefest of periods last season, Mauro Diaz was a revelation in Major League Soccer, arguably the most creative, most influential, most skilful playmaker the league had to offer. The superlatives lingering from that period were enough to garner – from some quarters – the diminutive Argentinean the title of predicted MLS MVP in 2015 practically before a ball had been kicked in anger in the campaign. And, apparently, before Diaz had had the chance to fully recover from an injury-plagued 2014.

Because then came the unthinkable, the possibility that what happened to Diaz roughly this time last year had reared its head again as March ticked into April. Last 26 April, as Dallas squandered 4-1 to DC United, Diaz left the field with a suspected knee injury. The fallout back then was somewhat byzantine, the Dallas faithful unsure when they would see their flair player in red and white again. One member of the local press pack alleged the injury, to his right knee, was season-ending, a claim the club swiftly denied. Injury prognoses are not the stuff of transparency – at least that offered for public consumption – in Dallas, as per club policy not to provide updates. Confirmation of the exact nature of the damage took its time to weave its way into the public domain. When it did, the word was he would be out for six to 10 weeks following a procedure on damaged cartilage. Most pertinently, what followed was the near collapse of the Frisco-based side’s season. Amid the intrigue and second-guessing, meanwhile, FC Dallas head coach Oscar Pareja, seemingly rattled, intimated he was tired of fielding questions over Diaz’s health.

Quite. Mere mention of Diaz and potential ailments sparks a dose of the jitters in Dallas. It’s a measure of his influence, an indication perhaps of just how many points his presence, on-form, could add to this talented team. Dallas were minus the 24-year-old for a sizable chunk of the year 2014. And on his return he was more of a bit-part player. Yet they overcame that horrific mid-season run of results, finding a formula that helped them into the 2014 playoffs where they eventually came up short against Seattle Sounders in the Western Conference semi-finals.

That only adds to the myth. Diaz had returned to the fray in time for Independence Day, though often more in essence than tangible output, the aftereffects of injury and suspension interrupting his contributions. What if? Without him, Dallas can be effective but somewhat one-dimensional. After his side’s 0-0 tie in Dallas earlier this season, Seattle head coach Sigi Schmid appeared to put his own spin on this limitation when he claimed the system was based on drawing fouls and exploiting winger Fabian Castillo’s pace. With Diaz, when he operates in full flow, Dallas can be an entirely different proposition: thoughtful, more creative and dynamic. In sum, last season’s dance around the true seriousness of Diaz’s condition only served to underscore the anchor point he occupies in the current FC Dallas jigsaw puzzle.

The symmetry with what has occurred so far this year is imperfect. But there have been conspicuously worrying signs. Alarm bells first rang when Diaz went off late in his team’s 2-0 away win against Philadelphia Union and failed to appear in the squad for the next encounter at home to Seattle a week later. That’s when the murmurs started to rise to the level of serious question marks, at least among some of those on the outside looking in. He was training alone, it emerged. The knee was troubling him again, some said. The hamstring troubles he suffered upon return from his knee injury last summer may be flaring up again, too, the naysayers speculated. More conspiratorial voices pondered the possibility of lurking interest in Diaz from South America and Europe as figurative actors in concert with his non-appearance.

He went on to miss the Dallas defeats to Portland Timbers and Colorado Rapids. The Diaz-shaped shadow of last season protruded once more. The script reads like Groundhog Day: A blistering start to the campaign, producing three wins in which Diaz plays a part, though this time round it is more nominal, less inspiring cast against his March 2014 standards. Then the former River Plate youngster exits under a cloud, and there’s a slide that begins with a draw and capitulates into two comprehensive defeats, the 4-0 mauling at home to Colorado particularly jarring given they were a team standing atop a poverty of goals, never mind wins.

The curse of club policy struck once more. Explanations of preventive, individualized training routines were muffled by speculation of an injury-prone prodigy. This might be where the image of a still-born talent starts to take rough shape, that of the fabled flair player cut down before his prime, on the road toward a career blighted by that which is most dreaded: degenerative knee problems. Not so, it would seem. In recent weeks, Pareja has batted away concerns over a recurrence of the historical injury. A club spokesman followed up Tuesday night with some eyewitness testimony of his own. As the attacking and defensive portions of the Dallas squad parted for separate training sessions, he looked on as Diaz mingled among the forwards, ready to engage, telling the Guardian the playmaker had at no point figured on the club’s injury list during the befuddling weeks since he last appeared in Philadelphia. He is back amid the melee, then, and a place on the bench during that lightning and thunderstorm-delayed spectacle with Toronto suggests he might be back where it matters imminently. Diaz himself, normally a retiring, understated figure, emerged to speak for himself before members of the local press prior to the Toronto fixture, reiterating what had previously been stated in explanation of his absence.

As storms go, the one over Frisco that delayed the game for more than three hours was more ferocious than anything overhanging Diaz. This time round, the absence may be more a case of clever management of a player’s idiosyncrasies, however much a part an old injury plays as a member of the supporting cast, than some kind of subterfuge. Yet the abundance of caution is indicative. Lessons learned from Diaz’s troubles last season would seem to be in play, the advice of a newly installed strength and conditioning coach guiding Pareja toward wrapping a still somewhat fragile commodity in the proverbial cotton wool. That man, Fabian Bazan, formerly of Mexican side Club Tijuana and the Venezuelan national team, helped encourage the strong-willed gaffer to put on his kid gloves and take Diaz away from matchday duties for a time and away from the rest of the squad for a separate training regimen beyond the breath of preseason. Pareja’s words in an interview with the Guardian prior to the start of the season seem illustrative: “We are aware of the challenge of the long season here, the travelling and the physical difficulties that the league may bring,” he said. “With Mauro, we know better now how we can manage his time and make him available the most we can.”

That match with Toronto snapped any resurfacing suggestions Dallas are lost without their young talisman. In the opening 20 minutes, they blew Toronto away with two well-worked goals and another plundered after a mistake in the Toronto rearguard. Albeit, a near collapse in the second half, aided by the weather’s prolonged interruption, demonstrated fallibilities, underscoring the need for the quite different option Diaz represents. His intelligent possession play, incisive, defence-splitting passes, and midfield trickery recall some of the audacious play displayed by Pareja when he wore the FC Dallas colours as a player. The lack of a viable alternative should Diaz’s troubles intervene at any kind of a frequent clip as the season progresses may not only rule him out of the MVP stakes but gnaw at the hopes of one of the league’s most fancied dark horses.