The St. Louis Cardinals rookie shortstop has been impressive in the first month of the season.

When the St. Louis Cardinals shortstop Jhonny Peralta went down with a thumb injury in spring training, I knew it would open the door for rookie Aledmys Diaz. But the question was how wide that door would open.

Despite a stellar spring training, John Mozeliak and company decided to sign former Met Ruben Tejada as insurance and a stopgap until Peralta could return. As fate would have it, the injury bug bit Tejada right before the season started and, there once again was Diaz.

Now, even with Tejada back, Diaz has still gotten some starts for the Cardinals at shortstop, and boy has the 25-year old been impressive. Yes, I know that Diaz has struggled with fielding his position at times. He already has five errors this year in 35 chances. I’m not defending the sloppy play. He has to clean that up, and he knows it. The booted double play earlier in the season against the Pirates likely cost the Cardinals the game. So, defensive miscues can certainly be crucial in the outcome of the game.

Still, when a rookie is hitting the ball like Diaz is right now, how can you not play him?

Last night Diaz finished 5-for-5 with two doubles and two RBI in an 11-2 win against the San Diego Padres. That performance puts him in some nice company early on in the season. As of today, Diaz is ranked fourth in the National League with 11 extra base hits. That puts him just three extra-base hits behind reigning MVP Bryce Harper. Diaz is also tied for second in all of baseball with his 8 doubles. The Cuban shortstop has come out raking in April.

Diaz stands out even more when just comparing him to this Cardinals roster. Diaz is tied for the club lead with catcher Yadier Molina and their 21 hits a piece on the season, and Diaz has done it in 20 less plate appearances than Yadi. Diaz’s 8 doubles rank first on the team, and he also leads the club with a .467 batting average (minimum 30 at bats – sorry, Eric Fryer). The young shorstop also leads the Cardinals in slugging percentage and OPS. Probably the most impressive stat so far is the fact that Diaz has only struck out 6.3 percent of the time — which leads the Cardinals by a landslide with Molina coming in at second with a 13.2 strikeout percentage.

It’s not only time for manager Mike Matheny to give Diaz more starts but to move the 25-year old further up in the lineup. Matheny has said before that he will play the hot hand, and so far he has backed up that statement. Giving rookie outfielder Jeremy Hazelbaker starts in the first homestand of the year paid off big time. Aside from playing favorites with unexplainably giving Matt Adams starts in the cleanup spot (another article for another day), Matheny has been pretty good about playing the hot hand.

That has to be the case with Diaz. He has only made 10 starts this month though and it’s time to give him more. Diaz has primarily batted 8th in the Cardinals lineup so far this year, but he should be hitting higher, at least until he cools off. Diaz should bat at least 7th, but I wouldn’t mind seeing him get a shot in the 5th or 6th slot and see if he can do damage there.

Diaz will certainly regress soon. His team-leading .475 BABIP means that he won’t be so lucky on balls in play. But for right now the Cardinals need to forget about Tejada’s defense and give the keys to Diaz. So far, Matheny and the Cardinals have treated Diaz like a nice rental car — take it for a drive when you need it and return it to the carshop at the end of the day. It’s time the Cardinals put a downpayment on this nice ride, fill it up with a full tank of gas and put the pedal to the metal.

What will be real interesting is seeing how long Diaz gets to keep the keys if he continues hitting like he has once Peralta comes back from his thumb injury. It would be a great problem to have. For now, it looks like the future could be bright for the Cardinals at shortstop.

Where do you think Diaz should bat in the lineup? Drop me a line on Twitter and let me know.