After missing all of last season following Tommy John elbow surgery, Francisco Liriano returned to the mound Sunday afternoon in Kansas City and started a major-league game for the first time since Sept. 13, 2006. He predictably struggled, allowing four runs on six hits and a career-high five walks, and was pulled from the game with two outs in the fifth inning after using 90 pitches to record just 14 outs. His final pitching line wasn't pretty:

Throughout his recovery there was talk that Liriano would attempt to return as a pitcher who relied less on his slider and more on his fastball and changeup, and that was certainly the case against the Royals. Liriano began the game with 10 straight fastballs, the first seven of which failed to crack 90 miles per hour, and seemed to save his slider for key spots and two-strike counts. That's quite different than 2006, when Liriano threw 43 percent fastballs, 38 percent sliders, and 19 percent changeups.

Determining what he threw Sunday was somewhat difficult because at times what appeared to be changeups seemed to hang like slow breaking balls and what appeared to be sliders looked more like curveballs because they lacked that 2006 bite (he did throw a curveball in the minors). Most of his pitches were clearly identifiable, but at times Liriano seemingly threw a sort of mashed-up "off-speed pitch" that appeared to move more than a changeup while coming to the plate slower than a slider.

MLB.com's incredibly detailed pitch-tracking system had all kinds of trouble consistently labeling each offering, and Dick Bremer and Bert Blyleven often failed to agree on what Liriano had just thrown while broadcasting the game. As a rough estimate based on MLB.com's tracking, Blyleven's commentary, my eyes, and some reports from people who were actually in the clubhouse following the game, Liriano threw 52 percent fastballs, 28 percent changeups, and 20 percent sliders.

In 2006 he was a fastball-slider pitcher who used his changeup sparingly, but Sunday he was a fastball-changeup pitcher who used his slider sparingly. Many people believe that relying so heavily on his slider is to blame for Liriano's elbow injury, and clearly the plan at this point is to make it a much smaller part of his arsenal. That may be the correct move, but the impact that a fundamental change in his approach figures to have on his performance has seemingly been overlooked.

No slider in the mix
Regardless of the injury and whether he'll ever fully recover, throwing his slider a fraction of the amount that he did before will hugely impact his results. Liriano didn't have filthy stuff and post a 2.16 ERA simply by virtue of being on the mound. He did so in large part because of a slider that hitters couldn't handle. Removing that from the mix even if he had stayed healthy would have drastically changed his results and removing it from the mix after surgery should be expected to do the same and then some.

Imagine for a moment that Liriano had avoided the elbow injury in 2006 and instead remained fully healthy to this day. Let's say that he followed up his great rookie season by winning 20 games with a 3.00 ERA last year and then announced this spring that he planned to rely far less on his slider going forward. It would seemingly be pretty safe to assume that decision would have a major impact on his performance, yet few people seem to have latched on to the same notion post-surgery.

All of which makes the speculation about whether or not we'll ever see "the Liriano of 2006" again a little off base, because even before examining how he threw, the Liriano who took the mound Sunday in Kansas City was much different than the Liriano who dominated the league as a rookie simply by virtue of what he threw. He could have thrown every pitch as well as he did in 2006 and still not come close to the same results, because the selection of pitches that he threw was so different.

Of course, that's a moot point for now because Liriano didn't come close to throwing his pitches as well as he did in 2006. His 2006 fastball averaged 94.7 miles per hour, but he reached 94 with just one pitch Sunday, threw nearly one-third of his fastballs in the 80s, and averaged 90.2. His 2006 slider averaged 87.7 MPH, but he never topped 82 with it Sunday and averaged 80.7. His 2006 changeup averaged 83.5 MPH, but was exclusively in the 77-81 range Sunday while averaging 79.2.

Now, it was cold in Kansas City and it's certainly not uncommon for pitchers to experience an initial drop in velocity after Tommy John surgery, so there's little reason for significant concern following one outing. With that said, it's noteworthy that regardless of which pitch Liriano threw his velocity was down between 5-7 percent from 2006. The difference between a 94.7 MPH fastball and a 90.2 MPH fastball is massive, and Sunday's slider barely resembled the overpowering pitch from 2006.

Beyond the change in approach and significant loss of velocity, Liriano also struggled to command his pitches. Only 51 of his 90 offerings were strikes, including just 10 first-pitch strikes out of 25 batters, and he handed out a career-high five walks after issuing four free passes just once in his previous 20 starts. He had an equally tough time throwing fastballs (55 percent) and non-fastballs (57 percent) for strikes, and completely lost a handle on several pitches. Here's what he said afterward:

My slider's where I want it to be. I just don't want to throw it that much right now. My fastball's not where I want it. When I try to throw it inside, it stays in the middle. Try to throw it outside, it just goes away high. It was good to get back, it was just too cold today. I can't feel my hands throwing the ball.

Liriano was inconsistent during spring training and struggled in two minor-league rehab outings, so it should come as no surprise that his first start back in the majors was discouraging, especially given the weather. His velocity and command were both way off from where they were pre-surgery, which is perhaps to be expected from someone who missed 18 months of action and is trying to transition into both a new approach to pitching and slightly altered mechanics along with simply getting his stuff back.

Sunday afternoon's start against the Royals didn't prove much of anything except that Liriano has a long road ahead of him, and we knew that already. The good news is that he threw 90 pitches without suffering an apparent setback and showed velocity that was certainly MLB-caliber even if it wasn't close to being up to his own standards. Liriano will surely get better if he can stay healthy, but how much better remains to be seen and for now his return may have created more questions than it answered.